Shingled solar cell module

ABSTRACT

A high efficiency configuration for a solar cell module comprises solar cells conductively bonded to each other in a shingled manner to form super cells, which may be arranged to efficiently use the area of the solar module, reduce series resistance, and increase module efficiency. The front surface metallization patterns on the solar cells may be configured to enable single step stencil printing, which is facilitated by the overlapping configuration of the solar cells in the super cells. A solar photovoltaic system may comprise two or more such high voltage solar cell modules electrically connected in parallel with each other and to an inverter. Solar cell cleaving tools and solar cell cleaving methods apply a vacuum between bottom surfaces of a solar cell wafer and a curved supporting surface to flex the solar cell wafer against the curved supporting surface and thereby cleave the solar cell wafer along one or more previously prepared scribe lines to provide a plurality of solar cells. An advantage of these cleaving tools and cleaving methods is that they need not require physical contact with the upper surfaces of the solar cell wafer. Solar cells are manufactured with reduced carrier recombination losses at edges of the solar cell, e.g., without cleaved edges that promote carrier recombination. The solar cells may have narrow rectangular geometries and may be advantageously employed in shingled (overlapping) arrangements to form super cells.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of International Patent ApplicationPCT/US2015/032472 titled “Shingled Solar Cell Module” and filed May 26,2015. International Patent Application PCT/US2015/032472 claims priorityto U.S. patent application Ser. No. 14/530,405 titled “Shingled SolarCell Module” and filed Oct. 31, 2014, U.S. patent application Ser. No.14/532,293 titled “Shingled Solar Cell Module” and filed Nov. 4, 2014,U.S. patent application Ser. No. 14/536,486 titled “Shingled Solar CellModule” and filed Nov. 7, 2014, U.S. patent application Ser. No.14/539,546 titled “Shingled Solar Cell Module” and filed Nov. 12, 2014,U.S. patent application Ser. No. 14/543,580 titled “Shingled Solar CellModule” and filed Nov. 17, 2014, U.S. patent application Ser. No.14/548,081 titled “Shingled Solar Cell Module” and filed Nov. 19, 2014,U.S. patent application Ser. No. 14/550,676 titled “Shingled Solar CellModule” and filed Nov. 21, 2014, U.S. patent application Ser. No.14/552,761 titled “Shingled Solar Cell Module” and filed Nov. 25, 2014,U.S. patent application Ser. No. 14/560,577 titled “Shingled Solar CellModule” and filed Dec. 4, 2014, U.S. patent application Ser. No.14/566,278 titled “Shingled Solar Cell Module” and filed Dec. 10, 2014,U.S. patent application Ser. No. 14/565,820 titled “Shingled Solar CellModule” and filed Dec. 10, 2014, U.S. patent application Ser. No.14/572,206 titled “Shingled Solar Cell Module” and filed Dec. 16, 2014,U.S. patent application Ser. No. 14/577,593 titled “Shingled Solar CellModule” and filed Dec. 19, 2014, U.S. patent application Ser. No.14/586,025 titled “Shingled Solar Cell Module” and filed Dec. 30, 2014,U.S. patent application Ser. No. 14/585,917 titled “Shingled Solar CellModule” and filed Dec. 30, 2014, U.S. patent application Ser. No.14/594,439 titled “Shingled Solar Cell Module” and filed Jan. 12, 2015,U.S. patent application Ser. No. 14/605,695 titled “Shingled Solar CellModule” and filed Jan. 26, 2015, U.S. Provisional Patent Application No.62/003,223 titled “Shingled Solar Cell Module” filed May 27, 2014, toU.S. Provisional Patent Application No. 62/036,215 titled “ShingledSolar Cell Module” filed Aug. 12, 2014, to U.S. Provisional PatentApplication No. 62/042,615 titled “Shingled Solar Cell Module” filedAug. 27, 2014, to U.S. Provisional Patent Application No. 62/048,858titled “Shingled Solar Cell Module” filed Sep. 11, 2014, to U.S.Provisional Patent Application No. 62/064,260 titled “Shingled SolarCell Module” filed Oct. 15, 2014, to U.S. Provisional Patent ApplicationNo. 62/064,834 titled “Shingled Solar Cell Module” filed Oct. 16, 2014,U.S. patent application Ser. No. 14/674,983 titled “Shingled Solar CellPanel Employing Hidden Taps” and filed Mar. 31, 2015, U.S. ProvisionalPatent Application No. 62/081,200 titled “Solar Cell Panel EmployingHidden Taps” and filed Nov. 18, 2014, U.S. Provisional PatentApplication No. 62/113,250 titled “Shingled Solar Cell Panel EmployingHidden Taps” and filed Feb. 6, 2015, U.S. Provisional Patent ApplicationNo. 62/082,904 titled “High Voltage Solar Panel” and filed Nov. 21,2014, U.S. Provisional Patent Application No. 62/103,816 titled “HighVoltage Solar Panel” and filed Jan. 15, 2015, U.S. Provisional PatentApplication No. 62/111,757 titled “High Voltage Solar Panel” and filedFeb. 4, 2015, U.S. Provisional Patent Application No. 62/134,176 titled“Solar Cell Cleaving Tools and Methods” and filed Mar. 17, 2015, U.S.Provisional Patent Application No. 62/150,426 titled “Shingled SolarCell Panel Comprising Stencil-Printed Cell Metallization” and filed Apr.21, 2015, U.S. Provisional Patent Application No. 62/035,624 titled“Solar Cells with Reduced Edge Carrier Recombination” and filed Aug. 11,2014, U.S. Design Pat. Application No. 29/506,415 filed Oct. 15, 2014,U.S. Design Pat. Application No. 29/506,755 filed Oct. 20, 2014, U.S.Design Pat. Application No. 29/508,323 filed Nov. 5, 2014, U.S. DesignPat. Application No. 29/509,586 filed Nov. 19, 2014, and to U.S. DesignPat. Application No. 29/509,588 filed Nov. 19, 2014. Each of the patentapplications in the preceding list is incorporated herein by referencein its entirety for all purposes.

FIELD OF THE INVENTION

The invention relates generally to solar cell modules in which the solarcells are arranged in a shingled manner.

BACKGROUND

Alternate sources of energy are needed to satisfy ever increasingworld-wide energy demands. Solar energy resources are sufficient in manygeographical regions to satisfy such demands, in part, by provision ofelectric power generated with solar (e.g., photovoltaic) cells.

SUMMARY

High efficiency arrangements of solar cells in a solar cell module, andmethods of making such solar modules, are disclosed herein.

In one aspect, a solar module comprises a series connected string ofN≧25 rectangular or substantially rectangular solar cells having onaverage a breakdown voltage greater than about 10 volts. The solar cellsare grouped into one or more super cells each of which comprises two ormore of the solar cells arranged in line with long sides of adjacentsolar cells overlapping and conductively bonded to each other with anelectrically and thermally conductive adhesive. No single solar cell orgroup of <N solar cells in the string of solar cells is individuallyelectrically connected in parallel with a bypass diode. Safe andreliable operation of the solar module is facilitated by effective heatconduction along the super cells through the bonded overlapping portionsof adjacent solar cells, which prevents or reduces formation of hotspots in reverse biased solar cells. The super cells may be encapsulatedin a thermoplastic olefin polymer sandwiched between glass front andback sheets, for example, further enhancing the robustness of the modulewith respect to thermal damage. In some variations, N is ≧30, ≧50, or≧100.

In another aspect, a super cell comprises a plurality of silicon solarcells each comprising rectangular or substantially rectangular front(sun side) and back surfaces with shapes defined by first and secondoppositely positioned parallel long sides and two oppositely positionedshort sides. Each solar cell comprises an electrically conductive frontsurface metallization pattern comprising at least one front surfacecontact pad positioned adjacent to the first long side, and anelectrically conductive back surface metallization pattern comprising atleast one back surface contact pad positioned adjacent the second longside. The silicon solar cells are arranged in line with first and secondlong sides of adjacent silicon solar cells overlapping and with frontsurface and back surface contact pads on adjacent silicon solar cellsoverlapping and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series. The front surface metallization pattern of each siliconsolar cell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one front surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

In another aspect, a super cell comprises a plurality of silicon solarcells each comprising rectangular or substantially rectangular front(sun side) and back surfaces with shapes defined by first and secondoppositely positioned parallel long sides and two oppositely positionedshort sides. Each solar cell comprises an electrically conductive frontsurface metallization pattern comprising at least one front surfacecontact pad positioned adjacent to the first long side, and anelectrically conductive back surface metallization pattern comprising atleast one back surface contact pad positioned adjacent the second longside. The silicon solar cells are arranged in line with first and secondlong sides of adjacent silicon solar cells overlapping and with frontsurface and back surface contact pads on adjacent silicon solar cellsoverlapping and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series. The back surface metallization pattern of each siliconsolar cell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one back surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

In another aspect, a method of making a string of solar cells comprisesdicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis. The method also comprises arranging therectangular silicon solar cells in line with long sides of adjacentsolar cells overlapping and conductively bonded to each other toelectrically connect the solar cells in series. The plurality ofrectangular silicon solar cells comprises at least one rectangular solarcell having two chamfered corners corresponding to corners or toportions of corners of the pseudo square wafer, and one or morerectangular silicon solar cells each lacking chamfered corners. Thespacing between parallel lines along which the pseudo square wafer isdiced is selected to compensate for the chamfered corners by making thewidth perpendicular to the long axis of the rectangular silicon solarcells that comprise chamfered corners greater than the widthperpendicular to the long axis of the rectangular silicon solar cellsthat lack chamfered corners, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

In another aspect, a super cell comprises a plurality of silicon solarcells arranged in line with end portions of adjacent solar cellsoverlapping and conductively bonded to each other to electricallyconnect the solar cells in series. At least one of the silicon solarcells has chamfered corners that correspond to corners or portions ofcorners of a pseudo square silicon wafer from which it was diced, atleast one of the silicon solar cells lacks chamfered corners, and eachof the silicon solar cells has a front surface of substantially the samearea exposed to light during operation of the string of solar cells.

In another aspect, a method of making two or more super cells comprisesdicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered corners. The method also comprisesremoving the chamfered corners from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered corners. The method further comprisesarranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength, and arranging the third plurality of rectangular silicon solarcells in line with long sides of adjacent rectangular silicon solarcells overlapping and conductively bonded to each other to electricallyconnect the third plurality of rectangular silicon solar cells in seriesto form a solar cell string having a width equal to the second length.

In another aspect, a method of making two or more super cells comprisesdicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered corners, arranging the first plurality of rectangularsilicon solar cells in line with long sides of adjacent rectangularsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the first plurality of rectangular silicon solarcells in series, and arranging the second plurality of rectangularsilicon solar cells in line with long sides of adjacent rectangularsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the second plurality of rectangular silicon solarcells in series.

In another aspect, a super cell comprises a plurality of silicon solarcells arranged in line in a first direction with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series, and anelongated flexible electrical interconnect with its long axis orientedparallel to a second direction perpendicular to the first direction,conductively bonded to a front or back surface of an end one of thesilicon solar cells at a plurality of discrete locations arranged alongthe second direction, running at least the full width of the end solarcell in the second direction, having a conductor thickness less than orequal to about 100 microns measured perpendicularly to the front or rearsurface of the end silicon solar cell, providing a resistance to currentflow in the second direction of less than or equal to about 0.012 Ohms,and configured to provide flexibility accommodating differentialexpansion in the second direction between the end silicon solar cell andthe interconnect for a temperature range of about −40° C. to about 85°C.

The flexible electrical interconnect may have a conductor thickness lessthan or equal to about 30 microns measured perpendicularly to the frontand rear surfaces of the end silicon solar cell, for example. Theflexible electrical interconnect may extend beyond the super cell in thesecond direction to provide for electrical interconnection to at least asecond super cell positioned parallel to and adjacent the super cell ina solar module. In addition, or alternatively, the flexible electricalinterconnect may extend beyond the super cell in the first direction toprovide for electrical interconnection to a second super cell positionedparallel to and in line with the super cell in a solar module.

In another aspect, a solar module comprises a plurality of super cellsarranged in two or more parallel rows spanning a width of the module toform a front surface of the module. Each super cell comprises aplurality of silicon solar cells arranged in line with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series. Atleast an end of a first super cell adjacent an edge of the module in afirst row is electrically connected to an end of a second super celladjacent the same edge of the module in a second row via a flexibleelectrical interconnect that is bonded to the front surface of the firstsuper cell at a plurality of discrete locations with an electricallyconductive adhesive bonding material, runs parallel to the edge of themodule, and at least a portion of which folds around the end of thefirst super cell and is hidden from view from the front of the module.

In another aspect, a method of making a super cell comprises laserscribing one or more scribe lines on each of one or more silicon solarcells to define a plurality of rectangular regions on the silicon solarcells, applying an electrically conductive adhesive bonding material tothe one or more scribed silicon solar cells at one or more locationsadjacent a long side of each rectangular region, separating the siliconsolar cells along the scribe lines to provide a plurality of rectangularsilicon solar cells each comprising a portion of the electricallyconductive adhesive bonding material disposed on its front surfaceadjacent a long side, arranging the plurality of rectangular siliconsolar cells in line with long sides of adjacent rectangular siliconsolar cells overlapping in a shingled manner with a portion of theelectrically conductive adhesive bonding material disposed in between,and curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

In another aspect, a method of making a super cell comprises laserscribing one or more scribe lines on each of one or more silicon solarcells to define a plurality of rectangular regions on the silicon solarcells, applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells,applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side, arranging theplurality of rectangular silicon solar cells in line with long sides ofadjacent rectangular silicon solar cells overlapping in a shingledmanner with a portion of the electrically conductive adhesive bondingmaterial disposed in between, and curing the electrically conductivebonding material, thereby bonding adjacent overlapping rectangularsilicon solar cells to each other and electrically connecting them inseries.

In another aspect, a method of making a solar module comprisesassembling a plurality of super cells, with each super cell comprising aplurality of rectangular silicon solar cells arranged in line with endportions on long sides of adjacent rectangular silicon solar cellsoverlapping in a shingled manner. The method also comprises curing anelectrically conductive bonding material disposed between theoverlapping end portions of adjacent rectangular silicon solar cells byapplying heat and pressure to the super cells, thereby bonding adjacentoverlapping rectangular silicon solar cells to each other andelectrically connecting them in series. The method also comprisesarranging and interconnecting the super cells in a desired solar moduleconfiguration in a stack of layers comprising an encapsulant, andapplying heat and pressure to the stack of layers to form a laminatedstructure.

Some variations of the method comprise curing or partially curing theelectrically conductive bonding material by applying heat and pressureto the super cells prior to applying heat and pressure to the stack oflayers to form the laminated structure, thereby forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure. In some variations, as each additionalrectangular silicon solar cell is added to a super cell during assemblyof the super cell, the electrically conductive adhesive bonding materialbetween the newly added solar cell and its adjacent overlapping solarcell is cured or partially cured before any other rectangular siliconsolar cell is added to the super cell. Alternatively, some variationscomprise curing or partially curing all of the electrically conductivebonding material in a super cell in the same step.

If the super cells are formed as partially cured intermediate products,the method may comprise completing the curing of the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form the laminated structure.

Some variations of the method comprise curing the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form a laminated structure, without forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

The method may comprise dicing one or more standard size silicon solarcells into rectangular shapes of smaller area to provide the rectangularsilicon solar cells. The electrically conductive adhesive bondingmaterial may be applied to the one or more silicon solar cells beforedicing the one or more silicon solar cells to provide the rectangularsilicon solar cells with pre-applied electrically conductive adhesivebonding material. Alternatively, the electrically conductive adhesivebonding material may be applied to the rectangular silicon solar cellsafter dicing the one or more silicon solar cells to provide therectangular silicon solar cells.

In one aspect, a solar module comprises a plurality of super cellsarranged in two or more parallel rows. Each super cell comprises aplurality of rectangular or substantially rectangular silicon solarcells arranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded directly to each other toelectrically connect the silicon solar cells in series. The solar panelalso comprises a first hidden tap contact pad located on a back surfaceof a first solar cell located at an intermediate position along a firstone of the super cells, and a first electrical interconnect conductivelybonded to the first hidden tap contact pad. The first electricalinterconnect comprises a stress relieving feature accommodatingdifferential thermal expansion between the interconnect and the siliconsolar cell to which it is bonded. The term “stress relieving feature” asused herein with respect to an interconnect may refer to a geometricalfeature such as a kink, loop, or slot, for example, to the thickness(e.g., very thin) of the interconnect, and/or to the ductility of theinterconnect. For example, the stress relieving feature may be that theinterconnect is formed from very thin copper ribbon.

The solar module may comprise a second hidden tap contact pad located ona back surface of a second solar cell located adjacent the first solarcell at an intermediate position along a second one of the super cellsin an adjacent super cell row, with the first hidden tap contact padelectrically connected to the second hidden tap contact pad through thefirst electrical interconnect. In such cases the first electricalinterconnect may extend across a gap between the first super cell andthe second super cell and be conductively bonded to the second hiddentap contact pad. Alternatively the electrical connection between thefirst and second hidden tap contact pads may include another electricalinterconnect conductively bonded to the second hidden tap contact padand electrically connected (e.g., conductively bonded) to the firstelectrical interconnect. Either interconnection scheme may optionallyextend across additional rows of super cells. For example, eitherinterconnection scheme may optionally extend across the full width ofthe module to interconnect a solar cell in each row via the hidden tapcontact pads.

The solar module may comprise a second hidden tap contact pad located ona back surface of a second solar cell located at another intermediateposition along the first one of the super cells, a second electricalinterconnect conductively bonded to the second hidden tap contact pad,and a bypass diode electrically connected by the first and secondelectrical interconnects in parallel with the solar cells locatedbetween the first hidden tap contact pad and the second hidden tapcontact pad.

In any of the above variations, the first hidden tap contact pad may beone of a plurality of hidden tap contact pads arranged on the backsurface of the first solar cell in a row running parallel to the longaxis of the first solar cell, with the first electrical interconnectconductively bonded to each of the plurality of hidden contacts andsubstantially spanning the length of the first solar cell along the longaxis. In addition or alternatively, the first hidden contact pad may beone of a plurality of hidden tap contact pads arranged on the backsurface of the first solar cell in a row running perpendicular to thelong axis of the first solar cell. In the latter case the row of hiddentap contact pads may be located adjacent a short edge of the first solarcell, for example. The first hidden contact pad may be one of aplurality of hidden tap contact pads arranged in a two dimensional arrayof the back surface of the first solar cell.

Alternatively, in any of the above variations the first hidden tapcontact pad may be located adjacent a short side of the back surface ofthe first solar cell, with the first electrical interconnect notextending substantially inward from the hidden tap contact pad along thelong axis of the solar cell, and the back surface metallization patternon the first solar cell providing a conductive path to the interconnectpreferably having a sheet resistance less than or equal to about 5 Ohmsper square, or less than or equal to about 2.5 Ohms per square. In suchcases the first interconnect may comprise, for example, two tabspositioned on opposite sides of the stress relieving feature, with oneof the tabs conductively bonded to the first hidden tap contact pad. Thetwo tabs may be of different lengths.

In any of the above variations the first electrical interconnect maycomprise alignment features identifying a desired alignment with thefirst hidden tap contact pad, or identifying a desired alignment with anedge of the first super cell, or identifying a desired alignment withthe first hidden tap contact pad and a desired alignment with an edge ofthe first super cell.

In another aspect a solar module comprises a glass front sheet, a backsheet, and a plurality of super cells arranged in two or more parallelrows between the glass front sheet and the back sheet. Each super cellcomprises a plurality of rectangular or substantially rectangularsilicon solar cells arranged in line with long sides of adjacent siliconsolar cells overlapping and flexibly conductively bonded directly toeach other to electrically connect the silicon solar cells in series. Afirst flexible electrical interconnect is rigidly conductively bonded toa first one of the super cells. The flexible conductive bonds betweenoverlapping solar cells provide mechanical compliance to the super cellsaccommodating a mismatch in thermal expansion between the super cellsand the glass front sheet in a direction parallel to the rows for atemperature range of about −40° C. to about 100° C. without damaging thesolar module. The rigid conductive bond between the first super cell andthe first flexible electrical interconnect forces the first flexibleelectrical interconnect to accommodate a mismatch in thermal expansionbetween the first super cell and the first flexible interconnect in adirection perpendicular to the rows for a temperature range of about−40° C. to about 180° C. without damaging the solar module.

The conductive bonds between overlapping adjacent solar cells within asuper cell may utilize a different conductive adhesive than theconductive bonds between the super cell and the flexible electricalinterconnect. The conductive bond at one side of at least one solar cellwithin a super cell may utilize a different conductive adhesive than theconductive bond at its other side. The conductive adhesive forming therigid bond between the super cell and the flexible electricalinterconnect may be a solder, for example. In some variations theconductive bonds between overlapping solar cells within a super cell areformed with a non-solder conductive adhesive, and the conductive bondbetween the super cell and the flexible electrical interconnect isformed with solder.

In some variations utilizing two different conductive adhesives as justdescribed, both conductive adhesives can be cured in the same processingstep (e.g., at the same temperature, at the same pressure, and/or in thesame time interval).

The conductive bonds between overlapping adjacent solar cells mayaccommodate differential motion between each cell and the glass frontsheet of greater than or equal to about 15 microns, for example.

The conductive bonds between overlapping adjacent solar cells may have athickness perpendicular to the solar cells of less than or equal toabout 50 microns and a thermal conductivity perpendicular to the solarcells greater than or equal to about 1.5 W/(meter-K), for example.

The first flexible electrical interconnect may withstand thermalexpansion or contraction of the first flexible interconnect of greaterthan or equal to about 40 microns, for example.

The portion of the first flexible electrical interconnect conductivelybonded to the super cell may be ribbon-like, formed from copper, andhave a thickness perpendicular to the surface of the solar cell to whichit is bonded of less than or equal to about 30 microns or less than orequal to about 50 microns, for example. The first flexible electricalinterconnect may comprise an integral conductive copper portion notbonded to the solar cell and providing a higher conductivity than theportion of the first flexible electrical interconnect that isconductively bonded to the solar cell. The first flexible electricalinterconnect may have a thickness perpendicular to the surface of thesolar cell to which it is bonded of less than or equal to about 30microns or less than or equal to about 50 microns, and a width greaterthan or equal to about 10 mm in the plane of the surface of the solarcell in a direction perpendicular to the flow of current though theinterconnect. The first flexible electrical interconnect may beconductively bonded to a conductor proximate to the solar cell thatprovides higher conductivity than the first electrical interconnect.

In another aspect, a solar module comprises a plurality of super cellsarranged in two or more parallel rows. Each super cell comprises aplurality of rectangular or substantially rectangular silicon solarcells arranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded directly to each other toelectrically connect the silicon solar cells in series. A hidden tapcontact pad which does not conduct significant current in normaloperation is located on a back surface of a first solar cell, which islocated at an intermediate position along a first one of the super cellsin a first one of the rows of super cells. The hidden tap contact pad iselectrically connected in parallel to at least a second solar cell in asecond one of the rows of super cells.

The solar module may comprise an electrical interconnect bonded to thehidden tap contact pad and electrically interconnecting the hidden tapcontact pad to the second solar cell. In some variations the electricalinterconnect does not substantially span the length of the first solarcell and a back surface metallization pattern on the first solar cellprovides a conductivity path to the hidden tap contact pad having asheet resistance less than or equal to about 5 Ohms per square.

The plurality of super cells may be arranged in three or more parallelrows spanning the width of the solar module perpendicular to the rows,and the hidden tap contact pad electrically connected to a hiddencontact pad on at least one solar cell in each of the rows of supercells to electrically connect all of the rows of super cells inparallel. In such variations the solar module may comprise at least onebus connection to at least one of the hidden tap contact pads, or to aninterconnect between hidden tap contact pads, that connects to a bypassdiode or other electronic device.

The solar module may comprise a flexible electrical interconnectconductively bonded to the hidden tap contact pad to electricallyconnect it to the second solar cell. The portion of the flexibleelectrical interconnect conductively bonded to the hidden tap contactpad may be for example ribbon-like, formed from copper, and have athickness perpendicular to the surface of the solar cell to which it isbonded of less than or equal to about 50 microns. The conductive bondbetween the hidden tap contact pad and the flexible electricalinterconnect may force the flexible electrical interconnect to withstanda mismatch in thermal expansion between the first solar cell and theflexible interconnect, and to accommodate relative motion between thefirst solar cell and the second solar cell resulting from thermalexpansion, for a temperature range of about −40° C. to about 180° C.without damaging the solar module.

In some variations, in operation of the solar module the first hiddencontact pad may conduct a current greater than the current generated inany single one of the solar cells.

Typically, the front surface of the first solar cell overlying the firsthidden tap contact pad is not occupied by contact pads or any otherinterconnect features. Typically, any area of the front surface of thefirst solar cell which is not overlapped by a portion of an adjacentsolar cell in the first super cell is not occupied by contact pads orany other interconnect features.

In some variations, in each super cell most of the cells do not havehidden tap contact pads. In such variations, the cells that have hiddentap contact pads may have a larger light collection area than the cellsthat do not have hidden tap contact pads.

In another aspect, a solar module comprises a glass front sheet, a backsheet, and a plurality of super cells arranged in two or more parallelrows between the glass front sheet and the back sheet. Each super cellcomprises a plurality of rectangular or substantially rectangularsilicon solar cells arranged in line with long sides of adjacent siliconsolar cells overlapping and flexibly conductively bonded directly toeach other to electrically connect the silicon solar cells in series. Afirst flexible electrical interconnect is rigidly conductively bonded toa first one of the super cells. The flexible conductive bonds betweenoverlapping solar cells are formed from a first conductive adhesive andhave a shear modulus less than or equal to about 800 megapascals. Therigid conductive bond between the first super cell and the firstflexible electrical interconnect is formed from a second conductiveadhesive and has a shear modulus of greater than or equal to about 2000megapascals.

The first conductive adhesive may have a glass transition temperature ofless than or equal to about 0° C., for example.

In some variations, the first conductive adhesive and the secondconductive adhesive are different, and both conductive adhesives can becured in the same processing step.

In some variations, the conductive bonds between overlapping adjacentsolar cells have a thickness perpendicular to the solar cells of lessthan or equal to about 50 micron and a thermal conductivityperpendicular to the solar cells greater than or equal to about 1.5W/(meter-K).

In one aspect, a solar module comprises a number N greater than or equalto about 150 of rectangular or substantially rectangular silicon solarcells arranged as a plurality of super cells in two or more parallelrows. Each super cell comprises a plurality of the silicon solar cellsarranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series. The super cells areelectrically connected to provide a high direct current voltage ofgreater than or equal to about 90 volts.

In one variation the solar module comprises one or more flexibleelectrical interconnects arranged to electrically connect the pluralityof super cells in series to provide the high direct current voltage. Thesolar module may comprise module level power electronics including aninverter that converts the high direct current voltage to an alternatingcurrent voltage. The module level power electronics may sense the highdirect current voltage and may operate the module at an optimumcurrent-voltage power point.

In another variation the solar module comprises module level powerelectronics electrically connected to individual pairs of adjacentseries connected rows of super cells, electrically connecting one ormore of the pairs of rows of super cells in series to provide the highdirect current voltage, and comprising an inverter that converts thehigh direct current voltage to an alternating current voltage.Optionally, the module level power electronics may sense the voltageacross each individual pair of rows of super cells and may operate eachindividual pair of rows of super cells at an optimum current-voltagepower point. Optionally, the module level power electronics may switchan individual pair of rows of super cells out of a circuit providing thehigh direct current voltage if the voltage across the pair of rows isbelow a threshold value.

In another variation the solar module comprises module level powerelectronics electrically connected to each individual row of supercells, electrically connecting two or more of the rows of super cells inseries to provide the high direct current voltage, and comprising aninverter that converts the high direct current voltage to an alternatingcurrent voltage. Optionally, the module level power electronics maysense the voltage across each individual row of super cells and mayoperate each individual row of super cells at an optimum current-voltagepower point. Optionally, the module level power electronics may switchan individual row of super cells out of a circuit providing the highdirect current voltage if the voltage across the row of super cells isbelow a threshold value.

In another variation the solar module comprises module level powerelectronics electrically connected to each individual super cell,electrically connecting two or more of the super cells in series toprovide the high direct current voltage, and comprising an inverter thatconverts the high direct current voltage to an alternating currentvoltage. Optionally, the module level power electronics may sense thevoltage across each individual super cell and may operate eachindividual super cell at an optimum current-voltage power point.Optionally, the module level power electronics may switch an individualsuper cell out of a circuit providing the high direct current voltage ifthe voltage across the super cell is below a threshold value.

In another variation each super cell in the module is electricallysegmented into a plurality of segments by hidden taps. The solar modulecomprises module level power electronics electrically connected to eachsegment of each super cell through the hidden taps, electricallyconnecting two or more segments in series to provide the high directcurrent voltage, and comprising an inverter that converts the highdirect current voltage to an alternating current voltage. Optionally,the module level power electronics may sense the voltage across eachindividual segment of each super cell and may operate each individualsegment at an optimum current-voltage power point. Optionally, themodule level power electronics may switch an individual segment out of acircuit providing the high direct current voltage if the voltage acrossthe segment is below a threshold value.

In any of the above variations the optimum current-voltage power pointmay be a maximum current-voltage power point.

In any of the above variations the module level power electronics maylack a direct current to direct current boost component.

In any of the above variations N may be greater than or equal to about200, greater than or equal to about 250, greater than or equal to about300, greater than or equal to about 350, greater than or equal to about400, greater than or equal to about 450, greater than or equal to about500, greater than or equal to about 550, greater than or equal to about600, greater than or equal to about 650, or greater than or equal toabout 700.

In any of the above variations the high direct current voltage may begreater than or equal to about 120 volts, greater than or equal to about180 volts, greater than or equal to about 240 volts, greater than orequal to about 300 volts, greater than or equal to about 360 volts,greater than or equal to about 420 volts, greater than or equal to about480 volts, greater than or equal to about 540 volts, or greater than orequal to about 600 volts.

In another aspect, a solar photovoltaic system comprises two or moresolar modules electrically connected in parallel, and an inverter. Eachsolar module comprises a number N greater than or equal to about 150rectangular or substantially rectangular silicon solar cells arranged asa plurality of super cells in two or more parallel rows. Each super cellin each module comprises two or more of the silicon solar cells in thatmodule arranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series. In each module the supercells are electrically connected to provide a high voltage directcurrent module output of greater than or equal to about 90 volts. Theinverter is electrically connected to the two or more solar modules toconvert their high voltage direct current output to an alternatingcurrent.

Each solar module may comprise one or more flexible electricalinterconnects arranged to electrically connect the super cells in thesolar module in series to provide the solar module's high voltage directcurrent output.

The solar photovoltaic system may comprise at least a third solar moduleelectrically connected in series with a first one of the two or moresolar modules that are electrically connected in parallel. In such casesthe third solar module may comprise a number N′ greater than or equal toabout 150 rectangular or substantially rectangular silicon solar cellsarranged as a plurality of super cells in two or more parallel rows.Each super cell in the third solar module comprises two or more of thesilicon solar cells in that module arranged in line with long sides ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series. In thethird solar module the super cells are electrically connected to providea high voltage direct current module output of greater than or equal toabout 90 volts.

Variations comprising a third solar module electrically connected inseries with a first one of the two or more solar modules, as justdescribed, may also comprise at least a fourth solar module electricallyconnected in series with a second one of the two or more solar modulesthat are electrically connected in parallel. The fourth solar module maycomprises a number N″ greater than or equal to about 150 rectangular orsubstantially rectangular silicon solar cells arranged as a plurality ofsuper cells in two or more parallel rows. Each super cell in the fourthsolar module comprises two or more of the silicon solar cells in thatmodule arranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series. In the fourth solar modulethe super cells are electrically connected to provide a high voltagedirect current module output of greater than or equal to about 90 volts.

The solar photovoltaic system may comprise fuses and/or blocking diodesarranged to prevent a short circuit occurring in any one of the solarmodules from dissipating power generated in the other solar modules.

The solar photovoltaic system may comprise positive and negative busesto which the two or more solar modules are electrically connected inparallel and to which the inverter is electrically connected.Alternatively, the solar photovoltaic system may comprise a combiner boxto which the two or more solar modules are electrically connected by aseparate conductor. The combiner box electrically connects the solarmodules in parallel, and may optionally comprise fuses and/or blockingdiodes arranged to prevent a short circuit occurring in any one of thesolar modules from dissipating power generated in the other solarmodules.

The inverter may be configured to operate the solar modules at a directcurrent voltage above a minimum value set to avoid reverse biasing asolar module.

The inverter may be configured to recognize a reverse bias conditionoccurring in one or more of the solar modules and operate the solarmodules at a voltage that avoids the reverse bias condition.

The solar photovoltaic system may be positioned on a roof top.

In any of the above variations N, N′, and N″ may be greater than orequal to about 200, greater than or equal to about 250, greater than orequal to about 300, greater than or equal to about 350, greater than orequal to about 400, greater than or equal to about 450, greater than orequal to about 500, greater than or equal to about 550, greater than orequal to about 600, greater than or equal to about 650, or greater thanor equal to about 700. N, N′, and N″ may have the same or differentvalues.

In any of the above variations the high direct current voltage providedby a solar module may be greater than or equal to about 120 volts,greater than or equal to about 180 volts, greater than or equal to about240 volts, greater than or equal to about 300 volts, greater than orequal to about 360 volts, greater than or equal to about 420 volts,greater than or equal to about 480 volts, greater than or equal to about540 volts, or greater than or equal to about 600 volts.

In another aspect a solar photovoltaic system comprises a first solarmodule comprising a number N greater than or equal to about 150rectangular or substantially rectangular silicon solar cells arranged asa plurality of super cells in two or more parallel rows. Each super cellcomprises a plurality of the silicon solar cells arranged in line withlong sides of adjacent silicon solar cells overlapping and conductivelybonded to each other to electrically connect the silicon solar cells inseries. The system also comprises an inverter. The inverter may be forexample a microinverter integrated with the first solar module. Thesuper cells in the first solar module are electrically connected toprovide a high direct current voltage of greater than or equal to about90 volts to the inverter, which converts the direct current to analternating current.

The first solar module may comprise one or more flexible electricalinterconnects arranged to electrically connect the super cells in thesolar module in series to provide the solar module's high voltage directcurrent output.

The solar photovoltaic system may comprise at least a second solarmodule electrically connected in series with the first solar module. Thesecond solar module may comprise a number N′ greater than or equal toabout 150 rectangular or substantially rectangular silicon solar cellsarranged as a plurality of super cells in two or more parallel rows.Each super cell in the second solar module comprises two or more of thesilicon solar cells in that module arranged in line with long sides ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series. In thesecond solar module the super cells are electrically connected toprovide a high voltage direct current module output of greater than orequal to about 90 volts.

The inverter (e.g., microinverter) may lack a direct current to directcurrent boost component.

In any of the above variations N and N′ may be greater than or equal toabout 200, greater than or equal to about 250, greater than or equal toabout 300, greater than or equal to about 350, greater than or equal toabout 400, greater than or equal to about 450, greater than or equal toabout 500, greater than or equal to about 550, greater than or equal toabout 600 greater than or equal to about 650, or greater than or equalto about 700. N and N′ may have the same or different values.

In any of the above variations, the high direct current voltage providedby a solar module may be greater than or equal to about 120 volts,greater than or equal to about 180 volts, greater than or equal to about240 volts, greater than or equal to about 300 volts, greater than orequal to about 360 volts, greater than or equal to about 420 volts,greater than or equal to about 480 volts, greater than or equal to about540 volts, or greater than or equal to about 600 volts.

In another aspect, a solar module comprises a number N greater than orequal to about 250 rectangular or substantially rectangular siliconsolar cells arranged as a plurality of series-connected super cells intwo or more parallel rows. Each super cell comprises a plurality of thesilicon solar cells arranged in line with long sides of adjacent siliconsolar cells overlapping and conductively bonded directly to each otherwith an electrically and thermally conductive adhesive to electricallyconnect the silicon solar cells in the super cell in series. The solarmodule comprises less than one bypass diode per 25 solar cells. Theelectrically and thermally conductive adhesive forms bonds betweenadjacent solar cells having a thickness perpendicular to the solar cellsof less than or equal to about 50 micron and a thermal conductivityperpendicular to the solar cells greater than or equal to about 1.5W/(meter-K).

The super cells may be encapsulated in a thermoplastic olefin layerbetween front and back sheets. The super cells and their encapsulant maybe sandwiched between glass front and back sheets.

The solar module may comprise, for example, less than one bypass diodeper 30 solar cells, or less than one bypass diode per 50 solar cells, orless than one bypass diode per 100 solar cells. The solar module maycomprise, for example, no bypass diodes, or only a single bypass diode,or not more than three bypass diodes, or not more than six bypassdiodes, or not more than ten bypass diodes.

The conductive bonds between overlapping solar cells may optionallyprovide mechanical compliance to the super cells accommodating amismatch in thermal expansion between the super cells and the glassfront sheet in a direction parallel to the rows for a temperature rangeof about −40° C. to about 100° C. without damaging the solar module.

In any of the above variations, N may be greater than or equal to about300, greater than or equal to about 350, greater than or equal to about400, greater than or equal to about 450, greater than or equal to about500, greater than or equal to about 550, greater than or equal to about600 greater than or equal to about 650, or greater than or equal toabout 700.

In any of the above variations, the super cells may be electricallyconnected to provide a high direct current voltage of greater than orequal to about 120 volts, greater than or equal to about 180 volts,greater than or equal to about 240 volts, greater than or equal to about300 volts, greater than or equal to about 360 volts, greater than orequal to about 420 volts, greater than or equal to about 480 volts,greater than or equal to about 540 volts, or greater than or equal toabout 600 volts.

A solar energy system may comprise the solar module of any of the abovevariations and an inverter (e.g., a microinverter) electricallyconnected to the solar module and configured to convert a DC output fromthe solar module to provide an AC output. The inverter may lack a DC toDC boost component. The inverter may be configured to operate the solarmodule at a direct current voltage above a minimum value set to avoidreverse biasing a solar cell. The minimum voltage value may betemperature dependent. The inverter may be configured to recognize areverse bias condition and operate the solar module at a voltage thatavoids the reverse bias condition. For example, the inverter may beconfigured to operate the solar module in a local maximum region of thesolar module's voltage-current power curve to avoid the reverse biascondition.

This specification discloses solar cell cleaving tools and solar cellcleaving methods.

In one aspect, a method of manufacturing solar cells comprises advancinga solar cell wafer along a curved surface, and applying a vacuum betweenthe curved surface and a bottom surface of the solar cell wafer to flexthe solar cell wafer against the curved surface and thereby cleave thesolar cell wafer along one or more previously prepared scribe lines toseparate a plurality of solar cells from the solar cell wafer. The solarcell wafer may be advanced continuously along the curved surface, forexample. Alternatively, the solar cell may be advanced along the curvedsurface in discrete movements.

The curved surface may be for example a curved portion of an uppersurface of a vacuum manifold that applies the vacuum to the bottomsurface of the solar cell wafer. The vacuum applied to the bottomsurface of the solar cell wafer by the vacuum manifold may vary alongthe direction of travel of the solar cell wafer and may be, for example,strongest in a region of the vacuum manifold in which the solar cellwafer is sequentially cleaved.

The method may comprise transporting the solar cell wafer along thecurved upper surface of the vacuum manifold with a perforated belt, withthe vacuum applied to the bottom surface of the solar cell wafer throughthe perforations in the perforated belt. The perforations may optionallybe arranged in the belt so that leading and trailing edges of the solarcell wafer along the direction of travel of the solar cell wafer mustoverlie at least one perforation in the belt and therefore be pulledtoward the curved surface by the vacuum, but this is not required.

The method may comprise advancing the solar cell wafer along a flatregion of the upper surface of the vacuum manifold to reach atransitional curved region of the upper surface of the vacuum manifoldhaving a first curvature, and then advancing the solar cell wafer into acleave region of the upper surface of the vacuum manifold where thesolar cell wafer is sequentially cleaved, with the cleave region of thevacuum manifold having a second curvature tighter than the firstcurvature. The method may further comprise advancing the cleaved solarcells into a post-cleave region of the vacuum manifold having a thirdcurvature tighter than the second curvature.

In any of the above variations, the method may comprise applying astronger vacuum between the solar cell wafer and the curved surface atone end of each scribe line then at the opposite end of each scribe lineto provide an asymmetric stress distribution along each scribe line thatpromotes nucleation and propagation of a single cleaving crack alongeach scribe line. Alternatively, or in addition, in any of the abovevariations the method may comprise orienting the scribe lines on thesolar cell wafer at an angle to the vacuum manifold so that for eachscribe line one end reaches a curved cleaving region of the vacuummanifold before the other end.

In any of the above variations, the method may comprise removing thecleaved solar cells from the curved surface before edges of the cleavedsolar cells touch. For example, the method may comprise removing thecells in a direction tangential or approximately tangential to thecurved surface of the manifold at a speed greater than the cells' speedof travel along the manifold. This may be accomplished with atangentially arranged moving belt, for example, or with any othersuitable mechanism.

In any of the above variations, the method may comprise scribing thescribe lines onto the solar cell wafer and applying an electricallyconductive adhesive bonding material to portions of the top or bottomsurface of the solar cell wafer prior to cleaving the solar cell waferalong the scribe lines. Each of the resulting cleaved solar cells maythen comprise a portion of the electrically conductive adhesive bondingmaterial disposed along a cleaved edge of its top or bottom surface. Thescribe lines may be formed before or after the electrically conductiveadhesive bonding material is applied using any suitable scribing method.The scribe lines may be formed by laser scribing, for example.

In any of the above variations, the solar cell wafer may be a square orpseudo square silicon solar cell wafer.

In another aspect, a method of making a string of solar cells comprisesarranging a plurality of rectangular solar cells in line with long sidesof adjacent rectangular solar cells overlapping in a shingled mannerwith electrically conductive adhesive bonding material disposed inbetween, and curing the electrically conductive bonding material tothereby bond adjacent overlapping rectangular solar cells to each otherand electrically connect them in series. The solar cells may bemanufactured, for example, by any of the variations of the method formanufacturing solar cells described above.

In one aspect, a method of making a string of solar cells comprisesforming a rear surface metallization pattern on each of one or moresquare solar cells, and stencil printing a complete front surfacemetallization pattern on each of the one or more square solar cellsusing a single stencil in a single stencil printing step. These stepsmay be performed in either order, or concurrently if suitable. By“complete front surface metallization pattern” it is meant that afterthe stencil printing step no additional metallization material need bedeposited on the front surface of the square solar cell to complete theformation of the front surface metallization. The method also comprisesseparating each square solar cell into two or more rectangular solarcells to form from the one or more square solar cells a plurality ofrectangular solar cells each comprising a complete front surfacemetallization pattern and a rear surface metallization pattern,arranging the plurality of rectangular solar cells in line with longsides of adjacent rectangular solar cells overlapping in a shingledmanner, and conductively bonding the rectangular solar cells in eachpair of adjacent overlapping rectangular solar cells to each other withan electrically conductive bonding material disposed between them toelectrically connect the front surface metallization pattern of one ofthe rectangular solar cells in the pair to the rear surfacemetallization pattern of the other of the rectangular solar cells in thepair, thereby electrically connecting the plurality of rectangular solarcells in series.

The stencil may be configured so that all portions of the stencil thatdefine one or more features of the front surface metallization patternon the one or more square solar cells are constrained by physicalconnections to other portions of the stencil to lie in a plane of thestencil during stencil printing.

The front surface metallization pattern on each rectangular solar cellmay for example comprise a plurality of fingers oriented perpendicularlyto the long sides of the rectangular solar cell, with none of thefingers in the front surface metallization pattern physically connectedto each other by the front surface metallization pattern.

This specification discloses solar cells with reduced carrierrecombination losses at edges of the solar cell, e.g., without cleavededges that promote carrier recombination, methods for manufacturing suchsolar cells, and the use of such solar cells in a shingled (overlapping)arrangements to form super cells.

In one aspect, a method of manufacturing a plurality of solar cellscomprises depositing one or more front surface amorphous silicon layerson a front surface of a crystalline silicon wafer, depositing one ormore rear surface amorphous silicon layers on a rear surface of thecrystalline silicon wafer on the opposite side of the crystallinesilicon wafer from the front surface, patterning the one or more frontsurface amorphous silicon layers to form one or more front surfacetrenches in the one or more front surface amorphous silicon layers,depositing a front surface passivating layer over the one or more frontsurface amorphous silicon layers and in the front surface trenches,patterning the one or more rear surface amorphous silicon layers to formone or more rear surface trenches in the one or more rear surfaceamorphous silicon layers, and depositing a rear surface passivatinglayer over the one or more rear surface amorphous silicon layers and inthe rear surface trenches. Each of the one or more rear surface trenchesis formed in line with a corresponding one of the front surfacetrenches. The method further comprises cleaving the crystalline siliconwafer at one or more cleavage planes, with each cleavage plane centeredor substantially centered on a different pair of corresponding front andrear surface trenches. In operation of the resulting solar cells thefront surface amorphous silicon layers are to be illuminated by light.

In some variations only the front surface trenches are formed, not therear surface trenches. In other variations only the rear surfacetrenches are formed, not the front surface trenches.

The method may comprise forming the one or more front surface trenchesto penetrate the front surface amorphous silicon layers to reach thefront surface of the crystalline silicon wafer, and/or forming the oneor more rear surface trenches to penetrate the one or more rear surfaceamorphous silicon layers to reach the rear surface of the crystallinesilicon wafer.

The method may comprise forming the front surface passivating layerand/or the rear surface passivating layer from a transparent conductiveoxide.

A pulsed laser or diamond tip may be used to initiate a cleaving point(e.g., of the order of 100 micron long). A CW laser and a cooling nozzlemay be used sequentially to induce high compressive and tensile thermalstress and guide the complete cleaving propagation in the crystallinesilicon wafer to separate the crystalline silicon wafer at the one ormore cleavage planes. Alternatively, the crystalline silicon wafer maybe mechanically cleaved at the one or more cleavage planes. Any suitablecleaving method may be used.

The one or more front surface amorphous crystalline silicon layers mayform an n-p junction with the crystalline silicon wafer, in which caseit may be preferable to cleave the crystalline silicon wafer from itsrear surface side. Alternatively, the one or more rear surface amorphouscrystalline silicon layers may form an n-p junction with the crystallinesilicon wafer, in which case it may be preferable to cleave thecrystalline silicon wafer from its front surface side.

In another aspect a method of manufacturing a plurality of solar cellscomprises forming one or more trenches in a first surface of acrystalline silicon wafer, depositing one or more amorphous siliconlayers on the first surface of the crystalline silicon wafer, depositinga passivating layer in the trenches and on the one or more amorphoussilicon layers on the first surface of the crystalline silicon wafer,depositing one or more amorphous silicon layers on a second surface ofthe crystalline silicon wafer on the opposite side of the crystallinesilicon wafer from the first surface, and cleaving the crystallinesilicon wafer at one or more cleavage planes, with each cleavage planecentered or substantially centered on a different one of the one or moretrenches.

The method may comprise forming the passivating layer from a transparentconductive oxide.

A laser may be used to induce thermal stress in the crystalline siliconwafer to cleave the crystalline silicon wafer at the one or morecleavage planes. Alternatively, the crystalline silicon wafer may bemechanically cleaved at the one or more cleavage planes. Any suitablecleaving method may be used.

The one or more front surface amorphous crystalline silicon layers mayform an n-p junction with the crystalline silicon wafer. Alternatively,the one or more rear surface amorphous crystalline silicon layers mayform an n-p junction with the crystalline silicon wafer.

In another aspect, a solar panel comprises a plurality of super cells,with each super cell comprising a plurality of solar cells arranged inline with end portions of adjacent solar cells overlapping in a shingledmanner and conductively bonded to each other to electrically connect thesolar cells in series. Each solar cell comprises a crystalline siliconbase, one or more first surface amorphous silicon layers disposed on afirst surface of the crystalline silicon base to form an n-p junction,one or more second surface amorphous silicon layers disposed on a secondsurface of the crystalline silicon base on the opposite side of thecrystalline silicon base from the first surface, and passivating layerspreventing carrier recombination at edges of the first surface amorphoussilicon layers, at edges of the second surface amorphous silicon layers,or at edges of the first surface amorphous silicon layers and edges ofthe second surface amorphous silicon layers. The passivating layers maycomprise a transparent conductive oxide.

The solar cells may be formed for example by any of the methodssummarized above or otherwise disclosed in this specification.

These and other embodiments, features and advantages of the presentinvention will become more apparent to those skilled in the art whentaken with reference to the following more detailed description of theinvention in conjunction with the accompanying drawings that are firstbriefly described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a cross-sectional diagram of a string of series-connectedsolar cells arranged in a shingled manner with the ends of adjacentsolar cells overlapping to form a shingled super cell.

FIG. 2A shows a diagram of the front (sun side) surface and frontsurface metallization pattern of an example rectangular solar cell thatmay be used to form shingled super cells.

FIGS. 2B and 2C show diagrams of the front (sun side) surface and frontsurface metallization patterns of two example rectangular solar cellshaving rounded corners that may be used to form shingled super cells

FIGS. 2D and 2E show diagrams of the rear surfaces and example rearsurface metallization patterns for the solar cell shown in FIG. 2A.

FIGS. 2F and 2G show diagrams of the rear surfaces and example rearsurface metallization patterns for the solar cells shown in FIGS. 2B and2C, respectively.

FIG. 2H shows a diagram of the front (sun side) surface and frontsurface metallization pattern of another example rectangular solar cellthat may be used to form shingled super cells. The front surfacemetallization pattern comprises discrete contact pads each of which issurrounded by a barrier configured to prevent uncured conductiveadhesive bonding material deposited on its contact pad from flowing awayfrom the contact pad.

FIG. 2I shows a cross-sectional view of the solar cell of FIG. 2H andidentifies detail of the front surface metallization pattern shown inexpanded view in FIGS. 2J and 2K that includes a contact pad andportions of a barrier surrounding the contact pad.

FIG. 2J shows an expanded view of detail from FIG. 2I.

FIG. 2K shows an expanded view of detail from FIG. 2I with uncuredconductive adhesive bonding material substantially confined to thelocation of the discrete contact pad by the barrier.

FIG. 2L shows a diagram of the rear surface and an example rear surfacemetallization pattern for the solar cell of FIG. 2H. The rear surfacemetallization pattern comprises discrete contact pads each of which issurrounded by a barrier configured to prevent uncured conductiveadhesive bonding material deposited on its contact pad from flowing awayfrom the contact pad.

FIG. 2M shows a cross-sectional view of the solar cell of FIG. 2L andidentifies detail of the rear surface metallization pattern shown inexpanded view in FIG. 2N that includes a contact pad and portions of abarrier surrounding the contact pad.

FIG. 2N shows an expanded view of detail from FIG. 2M.

FIG. 2O shows another variation of a metallization pattern comprising abarrier configured to prevent uncured conductive adhesive bondingmaterial from flowing away from a contact pad. The barrier abuts oneside of the contact pad and is taller than the contact pad.

FIG. 2P shows another variation of the metallization pattern of FIG. 2O,with the barrier abutting at least two sides of the contact pad

FIG. 2Q shows a diagram of the rear surface and an example rear surfacemetallization pattern for another example rectangular solar cell. Therear surface metallization pattern comprises a continuous contact padrunning substantially the length of a long side of the solar cell alongan edge of the solar cell. The contact pad is surrounded by a barrierconfigured to prevent uncured conductive adhesive bonding materialdeposited on the contact pad from flowing away from the contact pad.

FIG. 2R shows a diagram of the front (sun side) surface and frontsurface metallization pattern of another example rectangular solar cellthat may be used to form shingled super cells. The front surfacemetallization pattern comprises discrete contact pads arranged in a rowalong an edge of the solar cell and a long thin conductor runningparallel to and inboard from the row of contact pads. The long thinconductor forms a barrier configured to prevent uncured conductiveadhesive bonding material deposited on its contact pads from flowingaway from the contact pads and onto active areas of the solar cell.

FIG. 3A shows a diagram illustrating an example method by which astandard size and shape pseudo square silicon solar cell may beseparated (e.g., cut, or broken) into rectangular solar cells of twodifferent lengths that may be used to form shingled super cells.

FIGS. 3B and 3C show diagrams illustrating another example method bywhich a pseudo square silicon solar cell may be separated intorectangular solar cells. FIG. 3B shows the front surface of the waferand an example front surface metallization pattern. FIG. 3C shows therear surface of the wafer and an example rear surface metallizationpattern.

FIGS. 3D and 3E show diagrams illustrating an example method by which asquare silicon solar cell may be separated into rectangular solar cells.FIG. 3D shows the front surface of the wafer and an example frontsurface metallization pattern. FIG. 3E shows the rear surface of thewafer and an example rear surface metallization pattern.

FIG. 4A shows a fragmentary view of the front surface of an examplerectangular super cell comprising rectangular solar cells as shown forexample in FIG. 2A arranged in a shingled manner as shown in FIG. 1.

FIGS. 4B and 4C show front and rear views, respectively, of an examplerectangular super cell comprising “chevron” rectangular solar cellshaving chamfered corners, as shown for example in FIG. 2B, arranged in ashingled manner as shown in FIG. 1.

FIG. 5A shows a diagram of an example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately half thelength of the short sides of the module. Pairs of the super cells arearranged end-to-end to form rows with the long sides of the super cellsparallel to the short sides of the module.

FIG. 5B shows a diagram of another example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately the lengthof the short sides of the module. The super cells are arranged withtheir long sides parallel to the short sides of the module.

FIG. 5C shows a diagram of another example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately the lengthof the long side of the module. The super cells are arranged with theirlong sides parallel to the sides of the module.

FIG. 5D shows a diagram of an example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately half thelength of the long sides of the module. Pairs of the super cells arearranged end-to-end to form rows with the long sides of the super cellsparallel to the long sides of the module.

FIG. 5E shows a diagram of another example rectangular solar modulesimilar in configuration to that of FIG. 5C, in which all of the solarcells from which the super cells are formed are chevron solar cellshaving chamfered corners corresponding to corners of pseudo-squarewafers from which the solar cells were separated.

FIG. 5F shows a diagram of another example rectangular solar modulesimilar in configuration to that of FIG. 5C, in which the solar cellsfrom which the super cells are formed comprise a mixture of chevron andrectangular solar cells arranged to reproduce the shapes of thepseudo-square wafers from which they were separated.

FIG. 5G shows a diagram of another example rectangular solar modulesimilar in configuration to that of FIG. 5E, except that adjacentchevron solar cells in a super cell are arranged as mirror images ofeach other so that their overlapping edges are of the same length.

FIG. 6 shows an example arrangement of three rows of super cellsinterconnected with flexible electrical interconnects to put the supercells within each row in series with each other, and to put the rows inparallel with each other. These may be three rows in the solar module ofFIG. 5D, for example.

FIG. 7A shows example flexible interconnects that may be used tointerconnect super cells in series or in parallel. Some of the examplesexhibit patterning that increase their flexibility (mechanicalcompliance) along their long axes, along their short axes, or alongtheir long axes and their short axes. FIG. 7A shows examplestress-relieving long interconnect configurations that may be used inhidden taps to super cells as described herein or as interconnects tofront or rear surface super cell terminal contacts. FIGS. 7B-1 and 7B-2illustrate examples of out of-plane-stress relieving features. FIGS.7B-1 and 7B-2 show an example long interconnect configuration thatcomprises out-of plane stress relieving features and that may be used inhidden taps to super cells or as interconnects to front or rear surfacesuper cell terminal contacts.

FIG. 8A shows Detail A from FIG. 5D: a cross-sectional view of theexample solar module of FIG. 5D showing cross-sectional details offlexible electrical interconnects bonded to the rear surface terminalcontacts of the rows of super cells.

FIG. 8B shows Detail C from FIG. 5D: a cross-sectional view of theexample solar module of FIG. 5D showing cross-sectional details offlexible electrical interconnects bonded to the front (sunny side)surface terminal contacts of the rows of super cells.

FIG. 8C shows Detail B from FIG. 5D: a cross-sectional view of theexample solar module of FIG. 5D showing cross-sectional details offlexible interconnects arranged to interconnect two super cells in a rowin series.

FIG. 8D-8G show additional examples of electrical interconnects bondedto a front terminal contact of a super cell at an end of a row of supercells, adjacent an edge of a solar module. The example interconnects areconfigured to have a small foot print on the front surface of themodule.

FIG. 9A shows a diagram of another example rectangular solar modulecomprising six rectangular shingled super cells, with the long side ofeach super cell having a length of approximately the length of the longside of the module. The super cells are arranged in six rows that areelectrically connected in parallel with each other and in parallel witha bypass diode disposed in a junction box on the rear surface of thesolar module. Electrical connections between the super cells and thebypass diode are made through ribbons embedded in the laminate structureof the module.

FIG. 9B shows a diagram of another example rectangular solar modulecomprising six rectangular shingled super cells, with the long side ofeach super cell having a length of approximately the length of the longside of the module. The super cells are arranged in six rows that areelectrically connected in parallel with each other and in parallel witha bypass diode disposed in a junction box on the rear surface and nearan edge of the solar module. A second junction box is located on therear surface near an opposite edge of the solar module. Electricalconnection between the super cells and the bypass diode are made throughan external cable between the junction boxes.

FIG. 9C shows an example glass-glass rectangular solar module comprisingsix rectangular shingled super cells, with the long side of each supercell having a length of approximately the length of the long side of themodule. The super cells are arranged in six rows that are electricallyconnected in parallel with each other. Two junction boxes are mounted onopposite edges of the module, maximizing the active area of the module.

FIG. 9D shows a side view of the solar module illustrated in FIG. 9C.

FIG. 9E shows another example solar module comprising six rectangularshingled super cells, with the long side of each super cell having alength of approximately the length of the long side of the module. Thesuper cells are arranged in six rows, with three pairs of rowsindividually connected to a power management device on the solar module.

FIG. 9F shows another example solar module comprising six rectangularshingled super cells, with the long side of each super cell having alength of approximately the length of the long side of the module. Thesuper cells are arranged in six rows, with each row individuallyconnected to a power management device on the solar module.

FIGS. 9G and 9H show other embodiments of architectures for module levelpower management using shingled super cells.

FIG. 10A shows an example schematic electrical circuit diagram for asolar module as illustrated in FIG. 5B.

FIGS. 10B-1 and 10B-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Bhaving the schematic circuit diagram of FIG. 10A.

FIG. 11A shows an example schematic electrical circuit diagram for asolar module as illustrated in FIG. 5A.

FIGS. 11B-1 and 11B-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic electrical circuit diagram of FIG. 11A.

FIGS. 11C-1 and 11C-2 show another example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic electrical circuit diagram of FIG. 11A.

FIG. 12A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A.

FIGS. 12B-1 and 12B-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic circuit diagram of FIG. 12A.

FIGS. 12C-1, 12C-2, and 12C-3 show another example physical layout forvarious electrical interconnections for a solar module as illustrated inFIG. 5A having the schematic circuit diagram of FIG. 12A.

FIG. 13A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A.

FIG. 13B shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5B.

FIGS. 13C-1 and 13C-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Ahaving the schematic circuit diagram of FIG. 13A. Slightly modified, thephysical layout of FIGS. 13C-1 and 13C-2 is suitable for a solar moduleas illustrated in FIG. 5B having the schematic circuit diagram of FIG.13B.

FIG. 14A shows a diagram of another example rectangular solar modulecomprising a plurality of rectangular shingled super cells, with thelong side of each super cell having a length of approximately half thelength of the short side of the module. Pairs of the super cells arearranged end-to-end to form rows with the long sides of the super cellsparallel to the short side of the module.

FIG. 14B shows an example schematic circuit diagram for a solar moduleas illustrated in FIG. 14A.

FIGS. 14C-1 and 14C-2 show an example physical layout for variouselectrical interconnections for a solar module as illustrated in FIG.14A having the schematic circuit diagram of FIG. 14B.

FIG. 15 shows another example physical layout for various electricalinterconnections for a solar module as illustrated in FIG. 5B having theschematic circuit diagram of FIG. 10A.

FIG. 16 shows an example arrangement of a smart switch interconnectingtwo solar modules in series.

FIG. 17 shows a flow chart for an example method of making a solarmodule with super cells.

FIG. 18 shows a flow chart for another example method of making a solarmodule with super cells.

FIGS. 19A-19D show example arrangements by which super cells may becured with heat and pressure.

FIGS. 20A-20C schematically illustrate an example apparatus that may beused to cleave scribed solar cells. The apparatus may be particularlyadvantageous when used to cleave scribed super cells to which conductiveadhesive bonding material has been applied.

FIG. 21 shows an example white back sheet “zebra striped” with darklines that may be used in solar modules comprising parallel rows ofsuper cells to reduce visual contrast between the super cells andportions of the back sheet visible from the front of the module.

FIG. 22A shows a plan view of a conventional module utilizingtraditional ribbon connections under hot spot conditions. FIG. 22B showsa plan view of a module utilizing thermal spreading according toembodiments, also under hot spot conditions.

FIGS. 23A-23B show examples of super cell string layouts with chamferedcells.

FIGS. 24-25 show simplified cross-sectional views of arrays comprising aplurality of modules assembled in shingled configurations.

FIG. 26 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of the front (sunside) surface terminal electrical contacts of a shingled super cell to ajunction box on the rear side of the module.

FIG. 27 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module.

FIG. 28 shows a diagram of the rear (shaded) surface of a solar moduleillustrating another example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module.

FIG. 29 shows fragmentary cross-sectional and perspective diagrams oftwo super cells illustrating the use of a flexible interconnectsandwiched between overlapping ends of adjacent super cells toelectrically connect the super cells in series and to provide anelectrical connection to a junction box. FIG. 29A shows an enlarged viewof an area of interest in FIG. 29.

FIG. 30A shows an example super cell with electrical interconnectsbonded to its front and rear surface terminal contacts. FIG. 30B showstwo of the super cells of FIG. 30A interconnected in parallel.

FIGS. 31A-31C show diagrams of example back surface metallizationpatterns that may be employed to create hidden taps to super cells asdescribed herein.

FIGS. 32-33 show examples of the use of hidden taps with interconnectsthat run approximately the full width of the super cell.

FIGS. 34A-34C show examples of interconnects bonded to super cell rearsurface (FIG. 34A) and front surface (FIGS. 34B-34C) terminal contacts.

FIGS. 35-36 show examples of the use of hidden taps with shortinterconnects that span the gap between adjacent super cells but do notextend substantially inward along the long axis of the rectangular solarcells.

FIGS. 37A-1 to 37F-3 show example configurations for short hidden tapinterconnects comprising in-plane stress relieving features.

FIGS. 38A-1 to 38B-2 show example configurations for short hidden tapinterconnects comprising out-of-plane stress relieving features.

FIGS. 39A-1 and 39A-2 show example configurations for short hidden tapinterconnects comprising alignment features. FIGS. 39B-1 and 39B-2 showan example configuration for short hidden tap interconnects thatcomprises asymmetric tab lengths.

FIGS. 40 and 42A-44B show example solar module layouts employing hiddentaps.

FIG. 41 shows an example electrical schematic for the solar modulelayouts of FIGS. 40 and 42A-44B.

FIG. 45 shows current flow in an example solar module with a bypassdiode in conduction.

FIGS. 46A-46B show relative motion between solar module componentsresulting from thermal cycling in, respectively, a direction parallel tothe rows of super cells and a direction perpendicular to the rows ofsuper cells in the solar module.

FIGS. 47A-47B show, respectively, another example solar module layoutemploying hidden taps and the corresponding electrical schematic.

FIGS. 48A-48B show additional solar cell module layouts employing hiddentaps in combination with embedded bypass diodes.

FIGS. 49A-49B show block diagrams for, respectively, a solar moduleproviding a conventional DC voltage to a microinverter and a highvoltage solar module as described herein providing a high DC voltage toa microinverter.

FIGS. 50A-50B show example physical layout and electrical schematics forexample high voltage solar modules incorporating bypass diodes.

FIGS. 51A-55B show example architectures for module level powermanagement of high voltage solar modules comprising shingled supercells.

FIG. 56 shows an example arrangement of six super cells in six parallelrows with ends of adjacent rows offset and interconnected in series byflexible electrical interconnects.

FIG. 57A schematically illustrates a photovoltaic system comprising aplurality of high DC voltage shingled solar cell modules electricallyconnected in parallel with each other and to a string inverter. FIG. 57Bshows the photovoltaic system of FIG. 57A deployed on a roof top.

FIGS. 58A-58D show arrangements of current limiting fuses and blockingdiodes that may be used to prevent a high DC voltage shingled solar cellmodule having a short circuit from dissipating significant powergenerate in other high DC voltage shingled solar cell modules to whichit is electrically connected in parallel.

FIGS. 59A-59B show example arrangements in which two or more high DCvoltage shingled solar cell modules are electrically connected inparallel in a combiner box, which may include current limiting fuses andblocking diodes.

FIGS. 60A-60B each show a plot of current versus voltage and a plot ofpower versus voltage for a plurality of high DC voltage shingled solarcell modules electrically connected in parallel. The plots of FIG. 60Aare for an example case in which none of the modules include a reversebiased solar cell. The plots of FIG. 60B are for an example case inwhich some of the modules include one or more reverse biased solarcells.

FIG. 61A illustrates an example of a solar module utilizing about 1bypass diode per super cell. FIG. 61C illustrates an example of a solarmodule utilizing bypass diodes in a nested configuration. FIG. 61Billustrates an example configuration for a bypass diode connectedbetween two neighboring super cells using a flexible electricalinterconnect.

FIGS. 62A-62B schematically illustrate, respectively, side and top viewsof another example cleaving tool.

FIG. 63A schematically illustrates use of an example asymmetric vacuumarrangement to control nucleation and propagation of cracks along scribelines when cleaving a wafer. FIG. 63B schematically illustrates use ofan example symmetric vacuum arrangement that provides less control ofcleaving than the arrangement of FIG. 63A.

FIG. 64 schematically illustrates a top view of a portion of an examplevacuum manifold that may be used in the cleaving tool of FIGS. 62A-62B.

FIG. 65A and FIG. 65B provide, respectively, schematic illustrations oftop and perspective views of the example vacuum manifold of FIG. 64overlaid by a perforated belt.

FIG. 66 schematically illustrates a side view of an example vacuummanifold that may be used in the cleaving tool of FIGS. 62A-62B.

FIG. 67 schematically illustrates a cleaved solar cell overlying anexample arrangement of a perforated belt and a vacuum manifold.

FIG. 68 schematically illustrates the relative positions andorientations of a cleaved solar cell and an uncleaved portion of astandard size wafer from which the solar cell was cleaved in an examplecleaving process.

FIGS. 69A-69G schematically illustrate apparatus and methods by whichcleaved solar cells may be continuously removed from a cleaving tool.

FIGS. 70A-70C provide orthogonal views of another variation of theexample cleaving tool of FIGS. 62A-62B.

FIG. 71A and FIG. 71B provide perspective views of the example cleavingtool of FIGS. 70A-70C at two different stages of a cleaving process.

FIGS. 72A-74B illustrate details of the perforated belts and vacuummanifolds of the example cleaving tool of FIGS. 70A-70C.

FIGS. 75A-75G illustrate details of several example hole patterns thatmay be used for perforated vacuum belts in the example cleaving tool ofFIGS. 10A-10C.

FIG. 76 shows an example front surface metallization pattern on arectangular solar cell.

FIGS. 77A-77B show example rear surface metallization patterns onrectangular solar cells.

FIG. 78 shows an example front surface metallization pattern on a squaresolar cell that may be diced to form a plurality of rectangular solarcells each having the front surface metallization pattern shown in FIG.76.

FIG. 79 shows an example rear surface metallization pattern on a squaresolar cell that may be diced to form a plurality of rectangular solarcells each having the rear surface metallization pattern shown in FIG.77A.

FIG. 80 is a schematic diagram of a conventionally sized HIT solar cellbeing diced into narrow strip solar cells using conventional cleavingmethods, resulting in cleaved edges that promote carrier recombination.

FIGS. 81A-81J schematically illustrate steps in an example method ofdicing a conventionally sized HIT solar cell into narrow solar cellstrips lacking cleaved edges that promote carrier recombination.

FIGS. 82A-82J schematically illustrate steps in another example methodof dicing a conventionally sized HIT solar cell into narrow solar cellstrips lacking cleaved edges that promote carrier recombination.

DETAILED DESCRIPTION

The following detailed description should be read with reference to thedrawings, in which identical reference numbers refer to like elementsthroughout the different figures. The drawings, which are notnecessarily to scale, depict selective embodiments and are not intendedto limit the scope of the invention. The detailed descriptionillustrates by way of example, not by way of limitation, the principlesof the invention. This description will clearly enable one skilled inthe art to make and use the invention, and describes severalembodiments, adaptations, variations, alternatives and uses of theinvention, including what is presently believed to be the best mode ofcarrying out the invention.

As used in this specification and the appended claims, the singularforms “a,” “an,” and “the” include plural referents unless the contextclearly indicates otherwise. Also, the term “parallel” is intended tomean “parallel or substantially parallel” and to encompass minordeviations from parallel geometries rather than to require that anyparallel arrangements described herein be exactly parallel. The term“perpendicular” is intended to mean “perpendicular or substantiallyperpendicular” and to encompass minor deviations from perpendiculargeometries rather than to require that any perpendicular arrangementdescribed herein be exactly perpendicular. The term “square” is intendedto mean “square or substantially square” and to encompass minordeviations from square shapes, for example substantially square shapeshaving chamfered (e.g., rounded or otherwise truncated) corners. Theterm “rectangular” is intended to mean “rectangular or substantiallyrectangular” and to encompass minor deviations from rectangular shapes,for example substantially rectangular shapes having chamfered (e.g.,rounded or otherwise truncated) corners.

This specification discloses high-efficiency shingled arrangements ofsilicon solar cells in solar cell modules, as well as front and rearsurface metallization patterns and interconnects for solar cells thatmay be used in such arrangements. This specification also disclosesmethods for manufacturing such solar modules. The solar cell modules maybe advantageously employed under “one sun” (non-concentrating)illumination, and may have physical dimensions and electricalspecifications allowing them to be substituted for conventional siliconsolar cell modules.

FIG. 1 shows a cross-sectional view of a string of series-connectedsolar cells 10 arranged in a shingled manner with the ends of adjacentsolar cells overlapping and electrically connected to form a super cell100. Each solar cell 10 comprises a semiconductor diode structure andelectrical contacts to the semiconductor diode structure by whichelectric current generated in solar cell 10 when it is illuminated bylight may be provided to an external load.

In the examples described in this specification, each solar cell 10 is acrystalline silicon solar cell having front (sun side) surface and rear(shaded side) surface metallization patterns providing electricalcontact to opposite sides of an n-p junction, the front surfacemetallization pattern is disposed on a semiconductor layer of n-typeconductivity, and the rear surface metallization pattern is disposed ona semiconductor layer of p-type conductivity. However, any othersuitable solar cells employing any other suitable material system, diodestructure, physical dimensions, or electrical contact arrangement may beused instead of or in addition to solar cells 10 in the solar modulesdescribed in this specification. For example, the front (sun side)surface metallization pattern may be disposed on a semiconductor layerof p-type conductivity, and the rear (shaded side) surface metallizationpattern disposed on a semiconductor layer of n-type conductivity.

Referring again to FIG. 1, in super cell 100 adjacent solar cells 10 areconductively bonded to each other in the region in which they overlap byan electrically conducting bonding material that electrically connectsthe front surface metallization pattern of one solar cell to the rearsurface metallization pattern of the adjacent solar cell. Suitableelectrically conducting bonding materials may include, for example,electrically conducting adhesives and electrically conducting adhesivefilms and adhesive tapes, and conventional solders. Preferably, theelectrically conducting bonding material provides mechanical compliancein the bond between the adjacent solar cells that accommodates stressarising from mismatch between the coefficient of thermal expansion (CTE)of the electrically conducting bonding material and that of the solarcells (e.g., the CTE of silicon). To provide such mechanical compliance,in some variations the electrically conducting bonding material isselected to have a glass transition temperature of less than or equal toabout 0° C. To further reduce and accommodate stress parallel to theoverlapping edges of the solar cells arising from CTE mismatch, theelectrically conductive bonding material may optionally be applied onlyat discrete locations along the overlapping regions of the solar cellsrather than in a continuous line extending substantially the length ofthe edges of the solar cells

The thickness of the electrically conductive bond between adjacentoverlapping solar cells formed by the electrically conductive bondingmaterial, measured perpendicularly to the front and rear surfaces of thesolar cells, may be for example less than about 0.1 mm. Such a thin bondreduces resistive loss at the interconnection between cells, and alsopromotes flow of heat along the super cell from any hot spot in thesuper cell that might develop during operation. The thermal conductivityof the bond between solar cells may be, for example, ≧about 1.5Watts/(meter K).

FIG. 2A shows the front surface of an example rectangular solar cell 10that may be used in a super cell 100. Other shapes for solar cell 10 mayalso be used, as suitable. In the illustrated example the front surfacemetallization pattern of solar cell 10 includes a bus bar 15 positionedadjacent to the edge of one of the long sides of solar cell 10 andrunning parallel to the long sides for substantially the length of thelong sides, and fingers 20 attached perpendicularly to the bus bar andrunning parallel to each other and to the short sides of solar cell 10for substantially the length of the short sides.

In the example of FIG. 2A solar cell 10 has a length of about 156 mm, awidth of about 26 mm, and thus an aspect ratio (length of shortside/length of long side) of about 1:6. Six such solar cells may beprepared on a standard 156 mm×156 mm dimension silicon wafer, thenseparated (diced) to provide solar cells as illustrated. In othervariations, eight solar cells 10 having dimensions of about 19.5 mm×156mm, and thus an aspect ratio of about 1:8, may be prepared from astandard silicon wafer. More generally, solar cells 10 may have aspectratios of, for example, about 1:2 to about 1:20 and may be prepared fromstandard size wafers or from wafers of any other suitable dimensions.

FIG. 3A shows an example method by which a standard size and shapepseudo square silicon solar cell wafer 45 may be cut, broken, orotherwise divided to form rectangular solar cells as just described. Inthis example several full width rectangular solar cells 10L are cut fromthe central portion of the wafer, and in addition several shorterrectangular solar cells 10S are cut from end portions of the wafer andthe chamfered or rounded corners of the wafer are discarded. Solar cells10L may be used to form shingled super cells of one width, and solarcells 10S may be used to form shingled super cells of a narrower width.

Alternatively, the chamfered (e.g., rounded) corners may be retained onthe solar cells cut from end portions of the wafer. FIGS. 2B-2C show thefront surfaces of example “chevron” rectangular solar cells 10substantially similar to that of FIG. 2A, but having chamfered cornersretained from the wafer from which the solar cells were cut. In FIG. 2B,bus bar 15 is positioned adjacent to and runs parallel to the shorter ofthe two long sides for substantially the length of that side, andfurther extends at both ends at least partially around the chamferedcorners of the solar cell. In FIG. 2C, bus bar 15 is positioned adjacentto and runs parallel to the longer of the two long sides forsubstantially the length of that side. FIGS. 3B-3C show front and rearviews of a pseudo square wafer 45 that may be diced along the dashedlines shown in FIG. 3C to provide a plurality of solar cells 10 havingfront surface metallization patterns similar to that shown in FIG. 2A,and two chamfered solar cells 10 having front surface metallizationpatterns similar to that shown in FIG. 2B.

In the example front surface metallization pattern shown in FIG. 2B, thetwo end portions of bus bar 15 that extend around the chamfered cornersof the cell may each have a width that tapers (gradually narrows) withincreasing distance from the portion of the bus bar located adjacent thelong side of the cell. Similarly, in the example front surfacemetallization pattern shown in FIG. 3B, the two end portions of the thinconductor that interconnects discrete contact pads 15 extend around thechambered corners of the solar cell and taper with increasing distancefrom the long side of the solar cell along which the discrete contactpads are arranged. Such tapering is optional, but may advantageouslyreduce metal use and shading of the active region of the solar cellwithout significantly increasing resistive loss.

FIGS. 3D-3E show front and rear views of a perfect square wafer 47 thatmay be diced along the dashed lines shown in FIG. 3E to provide aplurality of solar cells 10 having front surface metallization patternssimilar to that shown in FIG. 2A.

Chamfered rectangular solar cells may be used to form super cellscomprising only chamfered solar cells. Additionally or alternatively,one or more such chamfered rectangular solar cells may be used incombination with one or more unchamfered rectangular solar cells (e.g.,FIG. 2A) to form a super cell. For example, the end solar cells of asuper cell may be chamfered solar cells, and the middle solar cellsunchamfered solar cells. If chamfered solar cells are used incombination with unchamfered solar cells in a super cell, or moregenerally in a solar module, it may be desirable to use dimensions forthe solar cells that result in the chamfered and unchamfered solar cellshaving the same front surface area exposed to light during operation ofthe solar cells. Matching the solar cell areas in this manner matchesthe current produced in the chamfered and unchamfered solar cells, whichimproves the performance of a series connected string that includes bothchamfered and unchamfered solar cells. The areas of chamfered andunchamfered solar cells cut from the same pseudo square wafer may bematched, for example, by adjusting locations of the lines along whichthe wafer is diced to make the chamfered solar cells slightly wider thanthe unchamfered solar cells in the direction perpendicular to their longaxes, to compensate for the missing corners on the chamfered solarcells.

A solar module may comprise only super cells formed exclusively fromunchamfered rectangular solar cells, or only super cells formed fromchamfered rectangular solar cells, or only super cells that includechamfered and unchamfered solar cells, or any combination of these threevariations of super cell.

In some instances portions of a standard size square or pseudo squaresolar cell wafer (e.g., wafer 45 or wafer 47) near the edges of thewafer may convert light to electricity with lower efficiency thanportions of the wafer located away from the edges. To improve theefficiency of the resulting rectangular solar cells, in some variationsone or more edges of the wafer are trimmed to remove the lowerefficiency portions before the wafer is diced. The portions trimmed fromthe edges of the wafer may have widths of about 1 mm to about 5 mm, forexample. Further, as shown in FIGS. 3B and 3D, the two end solar cells10 to be diced from a wafer may be oriented with their front surface busbars (or discrete contact pads) 15 along their outside edges and thusalong two of the edges of the wafer. Because in the super cellsdisclosed in this specification bus bars (or discrete contact pads) 15are typically overlapped by an adjacent solar cell, low light conversionefficiency along those two edges of the wafer typically does not affectperformance of the solar cells. Consequently, in some variations edgesof a square or pseudo square wafer oriented parallel to the short sidesof the rectangular solar cells are trimmed as just described, but edgesof the wafer oriented parallel to the long sides of rectangular solarcells are not. In other variations, one, two, three, or four edges of asquare wafer (e.g., wafer 47 in FIG. 3D) are trimmed as just described.In other variations, one, two, three, or four of the long edges of apseudo-square wafer are trimmed as just described.

Solar cells having long and narrow aspect ratios and areas less thanthat of a standard 156 mm×156 mm solar cell, as illustrated, may beadvantageously employed to reduce I²R resistive power losses in thesolar cell modules disclosed in this specification. In particular, thereduced area of solar cells 10 compared to standard size silicon solarcells decreases the current produced in the solar cell, directlyreducing resistive power loss in the solar cell and in a seriesconnected string of such solar cells. In addition, arranging suchrectangular solar cells in a super cell 100 so that current flowsthrough the super cell parallel to the short sides of the solar cellsmay reduce the distance that the current must flow through thesemiconductor material to reach fingers 20 in the front surfacemetallization pattern and reduce the required length of the fingers,which may also reduce resistive power loss.

As noted above, bonding overlapped solar cells 10 to each other in theiroverlapping region to electrically connect the solar cells in seriesreduces the length of the electrical connection between adjacent solarcells, compared to conventionally tabbed series-connected strings ofsolar cells. This also reduces resistive power loss.

Referring again to FIG. 2A, in the illustrated example the front surfacemetallization pattern on solar cell 10 comprises an optional bypassconductor 40 running parallel to and spaced apart from bus bar 15. (Sucha bypass conductor may also optionally be used in the metallizationpatterns shown in FIGS. 2B-2C, 3B, and 3D, and is also shown in FIG. 2Qin combination with discrete contact pads 15 rather than a continuousbus bar). Bypass conductor 40 interconnects fingers 20 to electricallybypass cracks that may form between bus bar 15 and bypass conductor 40.Such cracks, which may sever fingers 20 at locations near to bus bar 15,may otherwise isolate regions of solar cell 10 from bus bar 15. Thebypass conductor provides an alternative electrical path between suchsevered fingers and the bus bar. The illustrated example shows a bypassconductor 40 positioned parallel to bus bar 15, extending about the fulllength of the bus bar, and interconnecting every finger 20. Thisarrangement may be preferred but is not required. If present, the bypassconductor need not run parallel to the bus bar and need not extend thefull length of the bus bar. Further, a bypass conductor interconnects atleast two fingers, but need not interconnect all fingers. Two or moreshort bypass conductors may be used in place of a longer bypassconductor, for example. Any suitable arrangement of bypass conductorsmay be used. The use of such bypass conductors is described in greaterdetail in U.S. patent application Ser. No. 13/371,790, titled “SolarCell With Metallization Compensating For Or Preventing Cracking,” andfiled Feb. 13, 2012, which is incorporated herein by reference in itsentirety.

The example front surface metallization pattern of FIG. 2A also includesan optional end conductor 42 that interconnects fingers 20 at their farends, opposite from bus bar 15. (Such an end conductor may alsooptionally be used in the metallization patterns shown in FIGS. 2B-2C,3B, and 3D, and 2Q). The width of conductor 42 may be about the same asthat of a finger 20, for example. Conductor 42 interconnects fingers 20to electrically bypass cracks that may form between bypass conductor 40and conductor 42, and thereby provides a current path to bus bar 15 forregions of solar cell 10 that might otherwise be electrically isolatedby such cracks.

Although some of the illustrated examples show a front bus bar 15extending substantially the length of the long sides of solar cell 10with uniform width, this is not required. For example, as alluded toabove front bus bar 15 may be replaced by two or more front surfacediscrete contact pads 15 which may be arranged, for example, in linewith each other along a side of solar cell 10 as shown in FIGS. 2H, 2Q,and 3B for example. Such discrete contact pads may optionally beinterconnected by thinner conductors running between them, as shown forexample in the figures just mentioned. In such variations, the width ofthe contact pads measured perpendicularly to the long side of the solarcell may be for example about 2 to about 20 times that of the thinconductors interconnecting the contact pads. There may be a separate(e.g., small) contact pad for each finger in the front surfacemetallization pattern, or each contact pad may be connected to two ormore fingers. Front surface contact pads 15 may be square or have arectangular shape elongated parallel to the edge of the solar cell, forexample. Front surface contact pads 15 may have widths perpendicular tothe long side of the solar cell of about 1 mm to about 1.5 mm, forexample, and lengths parallel to the long side of the solar cell ofabout 1 mm to about 10 mm for example. The spacing between contact pads15 measured parallel to the long side of the solar cell may be about 3mm to about 30 mm, for example.

Alternatively, solar cell 10 may lack both a front bus bar 15 anddiscrete front contact pads 15 and include only fingers 20 in the frontsurface metallization pattern. In such variations, thecurrent-collecting functions that would otherwise be performed by afront bus bar 15 or contact pads 15 may instead be performed, orpartially performed, by the conductive material used to bond two solarcells 10 to each other in the overlapping configuration described above.

Solar cells lacking both a bus bar 15 and contact pads 15 may eitherinclude bypass conductor 40, or not include bypass conductor 40. If busbar 15 and contact pads 15 are absent, bypass conductor 40 may bearranged to bypass cracks that form between the bypass conductor and theportion of the front surface metallization pattern that is conductivelybonded to the overlapping solar cell.

The front surface metallization patterns, including bus bar or discretecontact pads 15, fingers 20, bypass conductor 40 (if present), and endconductor 42 (if present) may be formed, for example, from silver pasteconventionally used for such purposes and deposited, for example, byconventional screen printing methods. Alternatively, the front surfacemetallization patterns may be formed from electroplated copper. Anyother suitable materials and processes may be also used. In variationsin which the front surface metallization pattern is formed from silver,the use of discrete front surface contact pads 15 rather than acontinuous bus bar 15 along the edge of the cell reduces the amount ofsilver on the solar cell, which may advantageously reduce cost. Invariations in which the front surface metallization pattern is formedfrom copper or from another conductor less expensive than silver, acontinuous bus 15 may be employed without a cost disadvantage.

FIGS. 2D-2G, 3C, and 3E show example rear surface metallization patternsfor a solar cell. In these examples the rear surface metallizationpatterns include discrete rear surface contact pads 25 arranged alongone of the long edges of the rear surface of the solar cell and a metalcontact 30 covering substantially all of the remaining rear surface ofthe solar cell. In a shingled super cell, contact pads 25 are bonded forexample to a bus bar or to discrete contact pads arranged along the edgeof the upper surface of an adjacent overlapping solar cell toelectrically connect the two solar cells in series. For example, eachdiscrete rear surface contact pad 25 may be aligned with and bonded to acorresponding discrete front surface contact pad 15 on the front surfaceof the overlapping solar cell by electrically conductive bondingmaterial applied only to the discrete contact pads. Discrete contactpads 25 may be square (FIG. 2D) or have a rectangular shape elongatedparallel to the edge of the solar cell (FIGS. 2E-2G, 3C, 3E), forexample. Contact pads 25 may have widths perpendicular to the long sideof the solar cell of about 1 mm to about 5 mm, for example, and lengthsparallel to the long side of the solar cell of about 1 mm to about 10 mmfor example. The spacing between contact pads 25 measured parallel tothe long side of the solar cell may be about 3 mm to about 30 mm, forexample.

Contact 30 may be formed, for example, from aluminum and/orelectroplated copper. Formation of an aluminum back contact 30 typicallyprovides a back surface field that reduces back surface recombination inthe solar cell and thereby improves solar cell efficiency. If contact 30is formed from copper rather than aluminum, contact 30 may be used incombination with another passivation scheme (e.g., aluminum oxide) tosimilarly reduce back surface recombination. Discrete contact pads 25may be formed, for example, from silver paste. The use of discretesilver contact pads 25 rather than a continuous silver contact pad alongthe edge of the cell reduces the amount of silver in the rear surfacemetallization pattern, which may advantageously reduce cost.

Further, if the solar cells rely on a back surface field provided byformation of an aluminum contact to reduce back surface recombination,the use of discrete silver contacts rather than a continuous silvercontact may improve solar cell efficiency. This is because the silverrear surface contacts do not provide a back surface field and thereforetend to promote carrier recombination and produce dead (inactive)volumes in the solar cells above the silver contacts. In conventionallyribbon-tabbed solar cell strings those dead volumes are typically shadedby ribbons and/or bus bars on the front surface of the solar cell, andthus do not result in any extra loss of efficiency. In the solar cellsand super cells disclosed herein, however, the volume of the solar cellabove rear surface silver contact pads 25 is typically unshaded by anyfront surface metallization, and any dead volumes resulting from use ofsilver rear surface metallization reduce the efficiency of the cell. Theuse of discrete silver contact pads 25 rather than a continuous silvercontact pad along the edge of the rear surface of the solar cell thusreduces the volume of any corresponding dead zones and increases theefficiency of the solar cell.

In variations not relying on a back surface field to reduce back surfacerecombination, the rear surface metallization pattern may employ acontinuous bus bar 25 extending the length of the solar cell rather thandiscrete contact pads 25, as shown for example in FIG. 2Q. Such a busbar 25 may be formed for example, from tin or silver.

Other variations of the rear surface metallization patterns may employdiscrete tin contact pads 25. Variations of the rear surfacemetallization patterns may employ finger contacts similar to those shownin the front surface metallization patterns of FIGS. 2A-2C and may lackcontact pads and a bus bar.

Although the particular example solar cells shown in the figures aredescribed as having particular combinations of front and rear surfacemetallization patterns, more generally any suitable combination of frontand rear surface metallization patterns may be used. For example, onesuitable combination may employ a silver front surface metallizationpattern comprising discrete contact pads 15, fingers 20, and an optionalbypass conductor 40, and a rear surface metallization pattern comprisingan aluminum contact 30 and discrete silver contact pads 25. Anothersuitable combination may employ a copper front surface metallizationpattern comprising a continuous bus bar 15, fingers 20, and an optionalbypass conductor 40, and a rear surface metallization pattern comprisinga continuous bus bar 25 and a copper contact 30.

In the super cell manufacturing process (described in more detail below)the electrically conductive bonding material used to bond adjacentoverlapping solar cells in a super cell may be dispensed only onto(discrete or continuous) contact pads at the edge of the front or rearsurface of the solar cell, and not onto the surrounding portions of thesolar cell. This reduces use of material and, as described above, mayreduce or accommodate stress arising from CTE mismatch between theelectrically conductive bonding material and the solar cell. However,during or after deposition and prior to curing, portions of theelectrically conductive bonding material may tend to spread beyond thecontact pads and onto surrounding portions of the solar cell. Forexample, a binding resin portion of the electrically conductive bondingmaterial may be drawn off of a contact pad onto textured or porousadjacent portions of the solar cell surface by capillary forces. Inaddition, during the deposition process some of the conductive bondingmaterial may miss the contact pad and instead be deposited on adjacentportions of the solar cell surface, and possibly spread from there. Thisspreading and/or inaccurate deposition of the conductive bondingmaterial may weaken the bond between the overlapping solar cells and maydamage the portions of the solar cell onto which the conductive bondingmaterial has spread or been mistakenly deposited. Such spreading of theelectrically conductive bonding material may be reduced or prevented,for example, with a metallization pattern that forms a dam or barriernear or around each contact pad to retain the electrically conductivebonding material substantially in place.

As shown in FIGS. 2H-2K, for example, the front surface metallizationpattern may comprise discrete contact pads 15, fingers 20, and barriers17, with each barrier 17 surrounding a corresponding contact pad 15 andacting as a dam to form a moat between the contact pad and the barrier.Portions 19 of uncured conductive adhesive bonding material 18 that flowoff of the contact pads, or that miss the contact pads when dispensedonto the solar cell, may be confined by barriers 17 to the moats. Thisprevents the conductive adhesive bonding material from spreading furtherfrom the contact pads onto surrounding portions of the cell. Barriers 17may be formed from the same material as fingers 20 and contact pads 15(e.g., silver), for example, may have heights of about 10 microns toabout 40 microns, for example, and may have widths of about 30 micronsto about 100 microns, for example. The moat formed between a barrier 17and a contact pad 15 may have a width of about 100 microns to about 2mm, for example. Although the illustrated examples comprise only asingle barrier 17 around each front contact pad 15, in other variationstwo or more such barriers may be positioned concentrically, for example,around each contact pad. A front surface contact pad and its one or moresurrounding barriers may form a shape similar to a “bulls-eye” target,for example. As shown in FIG. 2H, for example, barriers 17 mayinterconnect with fingers 20 and with the thin conductorsinterconnecting contact pads 15.

Similarly, as shown in FIGS. 2L-2N, for example, the rear surfacemetallization pattern may comprise (e.g., silver) discrete rear contactpads 25, (e.g., aluminum) contact 30 covering substantially all of theremaining rear surface of the solar cell, and (e.g., silver) barriers27, with each barrier 27 surrounding a corresponding rear contact pad 25and acting as a dam to form a moat between the contact pad and thebarrier. A portion of contact 30 may fill the moat, as illustrated.Portions of uncured conductive adhesive bonding material that flow offof contact pads 25, or that miss the contact pads when dispensed ontothe solar cell, may be confined by barriers 27 to the moats. Thisprevents the conductive adhesive bonding material from spreading furtherfrom the contact pads onto surrounding portions of the cell. Barriers 27may have heights of about 10 microns to about 40 microns, for example,and may have widths of about 50 microns to about 500 microns, forexample. The moat formed between a barrier 27 and a contact pad 25 mayhave a width of about 100 microns to about 2 mm, for example. Althoughthe illustrated examples comprise only a single barrier 27 around eachrear surface contact pad 25, in other variations two or more suchbarriers may be positioned concentrically, for example, around eachcontact pad. A rear surface contact pad and its one or more surroundingbarriers may form a shape similar to a “bulls-eye” target, for example.

A continuous bus bar or contact pad running substantially the length ofthe edge of a solar cell may also be surrounded by a barrier thatprevents spreading of the conductive adhesive bonding material. Forexample, FIG. 2Q shows such a barrier 27 surrounding a rear surface busbar 25. A front surface bus bar (e.g., bus bar 15 in FIG. 2A) may besimilarly surrounded by a barrier. Similarly, a row of front or rearsurface contact pads may be surrounded as a group by such a barrier,rather than individually surrounded by separate barriers.

Rather than surrounding a bus bar or one or more contact pads as justdescribed, a feature of the front or rear surface metallization patternmay form a barrier running substantially the length of the solar cellparallel to the overlapped edge of the solar cell, with the bus bar orcontact pads positioned between the barrier and the edge of the solarcell. Such a barrier may do double duty as a bypass conductor (describedabove). For example, in FIG. 2R bypass conductor 40 provides a barrierthat tends to prevent uncured conductive adhesive bonding material oncontact pads 15 from spreading onto the active area of the front surfaceof the solar cell. A similar arrangement may be used for rear surfacemetallization patterns.

Barriers to the spread of conductive adhesive bonding material may bespaced apart from contact pads or bus bars to form a moat as justdescribed, but this is not required. Such barriers may instead abut acontact pad or bus bar, as shown in FIG. 2O or 2P for example. In suchvariations the barrier is preferably taller than the contact pad or busbar, to retain the uncured conductive adhesive bonding material on thecontact pad or bus bar. Although FIGS. 2O and 2P show portions of afront surface metallization pattern, similar arrangements may be usedfor rear surface metallization patterns.

Barriers to the spread of conductive adhesive bonding material and/ormoats between such barriers and contact pads or bus bars, and anyconductive adhesive bonding material that has spread into such moats,may optionally lie within the region of the solar cell surfaceoverlapped by the adjacent solar cell in the super cell, and thus behidden from view and shielded from exposure to solar radiation.

Alternatively or in addition to the use of barriers as just described,the electrically conductive bonding material may be deposited using amask or by any other suitable method (e.g., screen printing) allowingaccurate deposition and thus requiring reduced amounts of electricallyconductive bonding material that are less likely to spread beyond thecontact pads or miss the contact pads during deposition.

More generally, solar cells 10 may employ any suitable front and rearsurface metallization patterns.

FIG. 4A shows a portion of the front surface of an example rectangularsuper cell 100 comprising solar cells 10 as shown in FIG. 2A arranged ina shingled manner as shown in FIG. 1. As a result of the shinglinggeometry, there is no physical gap between pairs of solar cells 10. Inaddition, although bus bar 15 of the solar cell 10 at one end of supercell 100 is visible, the bus bars (or front surface contact pads) of theother solar cells are hidden beneath overlapping portions of adjacentsolar cells. As a consequence, super cell 100 efficiently uses the areait takes up in a solar module. In particular, a larger portion of thatarea is available to produce electricity than is the case forconventionally tabbed solar cell arrangements and solar cellarrangements including numerous visible bus bars on the illuminatedsurface of the solar cells. FIGS. 4B-4C show front and rear views,respectively, of another example super cell 100 comprising primarilychamfered chevron rectangular silicon solar cells but otherwise similarto that of FIG. 4A.

In the example illustrated in FIG. 4A, bypass conductors 40 are hiddenby overlapping portions of adjacent cells. Alternatively, solar cellscomprising bypass conductors 40 may be overlapped similarly to as shownin FIG. 4A without covering the bypass conductors.

The exposed front surface bus bar 15 at one end of super cell 100 andthe rear surface metallization of the solar cell at the other end ofsuper cell 100 provide negative and positive (terminal) end contacts forthe super cell that may be used to electrically connect super cell 100to other super cells and/or to other electrical components as desired.

Adjacent solar cells in super cell 100 may overlap by any suitableamount, for example by about 1 millimeter (mm) to about 5 mm.

As shown in FIGS. 5A-5G, for example, shingled super cells as justdescribed may efficiently fill the area of a solar module. Such solarmodules may be square or rectangular, for example. Rectangular solarmodules as illustrated in FIGS. 5A-5G may have shorts sides having alength, for example, of about 1 meter and long sides having a length,for example, of about 1.5 to about 2.0 meters. Any other suitable shapesand dimensions for the solar modules may also be used. Any suitablearrangement of super cells in a solar module may be used.

In a square or rectangular solar module, the super cells are typicallyarranged in rows parallel to the short or long sides of the solarmodule. Each row may include one, two, or more super cells arrangedend-to-end. A super cell 100 forming part of such a solar module mayinclude any suitable number of solar cells 10 and be of any suitablelength. In some variations super cells 100 each have a lengthapproximately equal to the length of the short sides of a rectangularsolar module of which they are a part. In other variations super cells100 each have a length approximately equal to one half the length of theshort sides of a rectangular solar module of which they are a part. Inother variations super cells 100 each have a length approximately equalto the length of the long sides of a rectangular solar module of whichthey are a part. In other variations super cells 100 each have a lengthapproximately equal to one half the length of the long sides of arectangular solar module of which they are a part. The number of solarcells required to make super cells of these lengths depends of course onthe dimensions of the solar module, the dimensions of the solar cells,and the amount by which adjacent solar cells overlap. Any other suitablelengths for super cells may also be used.

In variations in which a super cell 100 has a length approximately equalto the length of the short sides of a rectangular solar module, thesuper cell may include, for example, 56 rectangular solar cells havingdimensions of about 19.5 millimeters (mm) by about 156 mm, with adjacentsolar cells overlapped by about 3 mm. Eight such rectangular solar cellsmay be separated from a conventional square or pseudo square 156 mmwafer. Alternatively such a super cell may include, for example, 38rectangular solar cells having dimensions of about 26 mm by about 156mm, with adjacent solar cells overlapped by about 2 mm. Six suchrectangular solar cells may be separated from a conventional square orpseudo square 156 mm wafer. In variations in which a super cell 100 hasa length approximately equal to half the length of the short sides of arectangular solar module, the super cell may include, for example, 28rectangular solar cells having dimensions of about 19.5 millimeters (mm)by about 156 mm, with adjacent solar cells overlapped by about 3 mm.Alternatively, such a super cell may include, for example, 19rectangular solar cells having dimensions of about 26 mm by about 156mm, with adjacent solar cells overlapped by about 2 mm.

In variations in which a super cell 100 has a length approximately equalto the length of the long sides of a rectangular solar module, the supercell may include, for example, 72 rectangular solar cells havingdimensions of about 26 mm by about 156 mm, with adjacent solar cellsoverlapped by about 2 mm. In variations in which a super cell 100 has alength approximately equal to one half the length of the long sides of arectangular solar module, the super cell may include, for example, 36rectangular solar cells having dimensions of about 26 mm by about 156mm, with adjacent solar cells overlapped by about 2 mm.

FIG. 5A shows an example rectangular solar module 200 comprising twentyrectangular super cells 100, each of which has a length approximatelyequal to one half the length of the short sides of the solar module. Thesuper cells are arranged end-to-end in pairs to form ten rows of supercells, with the rows and the long sides of the super cells orientedparallel to the short sides of the solar module. In other variations,each row of super cells may include three or more super cells. Also, asimilarly configured solar module may include more or fewer rows ofsuper cells than shown in this example. (FIG. 14A for example shows asolar module comprising twenty-four rectangular super cells arranged intwelve rows of two super cells each).

Gap 210 shown in FIG. 5A facilitates making electrical contact to frontsurface end contacts (e.g., exposed bus bars or discrete contacts 15) ofsuper cells 100 along the center line of the solar module, in variationsin which the super cells in each row are arranged so that at least oneof them has a front surface end contact on the end of the super celladjacent to the other super cell in the row. For example, the two supercells in a row may be arranged with one super cell having its frontsurface terminal contact along the center line of the solar module andthe other super cell having its rear surface terminal contact along thecenter line of the solar module. In such an arrangement the two supercells in a row may be electrically connected in series by aninterconnect arranged along the center line of the solar module andbonded to the front surface terminal contact of one super cell and tothe rear surface terminal contact of the other super cell. (See e.g.FIG. 8C discussed below). In variations in which each row of super cellsincludes three or more super cells, additional gaps between super cellsmay be present and may similarly facilitate making electrical contact tofront surface end contacts that are located away from the sides of thesolar module.

FIG. 5B shows an example rectangular solar module 300 comprising tenrectangular super cells 100, each of which has a length approximatelyequal to the length of the short sides of the solar module. The supercells are arranged as ten parallel rows with their long sides orientedparallel to the short sides of the module. A similarly configured solarmodule may include more or fewer rows of such side-length super cellsthan shown in this example.

FIG. 5B also shows what solar module 200 of FIG. 5A looks like whenthere are no gaps between adjacent super cells in the rows of supercells in solar module 200. Gap 210 of FIG. 5A can be eliminated, forexample, by arranging the super cells so that both super cells in eachrow have their back surface end contacts along the center line of themodule. In this case the super cells may be arranged nearly abuttingeach other with little or no extra gap between them because no access tothe front surface of the super cell is required along the center of themodule. Alternatively, two super cells 100 in a row may be arranged withone having its front surface end contact along a side of the module andits rear surface end contact along the center line of the module, theother having its front surface end contact along the center line of themodule and its rear surface end contact along the opposite side of themodule, and the adjacent ends of the super cells overlapping. A flexibleinterconnect may be sandwiched between the overlapping ends of the supercells, without shading any portion of the front surface of the solarmodule, to provide an electrical connection to the front surface endcontact of one of the super cells and the rear surface end contact ofthe other super cell. For rows containing three or more super cellsthese two approaches may be used in combination.

The super cells and rows of super cells shown in FIGS. 5A-5B may beinterconnected by any suitable combination of series and parallelelectrical connections, for example as described further below withrespect to FIGS. 10A-15. The interconnections between super cells may bemade, for example, using flexible interconnects similarly to asdescribed below with respect to FIGS. 5C-5G and subsequent figures. Asdemonstrated by many of the examples described in this specification,the super cells in the solar modules described herein may beinterconnected by a combination of series and parallel connections toprovide an output voltage for the module substantially the same as thatof a conventional solar module. In such cases the output current fromthe solar module may also be substantially the same as that for aconventional solar module. Alternatively, as further described below thesuper cells in a solar module may be interconnected to provide asignificantly higher output voltage from the solar module than thatprovided by conventional solar modules.

FIG. 5C shows an example rectangular solar module 350 comprising sixrectangular super cells 100, each of which has a length approximatelyequal to the length of the long sides of the solar module. The supercells are arranged as six parallel rows with their long sides orientedparallel to the long sides of the module. A similarly configured solarmodule may include more or fewer rows of such side-length super cellsthan shown in this example. Each super cell in this example (and inseveral of the following examples) comprises 72 rectangular solar cellseach having a width approximately equal to ⅙ the width of a 156 mmsquare or pseudo square wafer. Any other suitable number of rectangularsolar cells of any other suitable dimensions may also be used. In thisexample the front surface terminal contacts of the super cells areelectrically connected to each other with flexible interconnects 400positioned adjacent to and running parallel to the edge of one shortside of the module. The rear surface terminal contacts of the supercells are similarly connected to each other by flexible interconnectspositioned adjacent to and running parallel to the edge of the othershort side, behind the solar module. The rear surface interconnects arehidden from view in FIG. 5C. This arrangement electrically connects thesix module-length super cells in parallel. Details of the flexibleinterconnects and their arrangement in this and other solar moduleconfigurations are discussed in more detail below with respect to FIGS.6-8G.

FIG. 5D shows an example rectangular solar module 360 comprising twelverectangular super cells 100, each of which has a length approximatelyequal to one half the length of the long sides of the solar module. Thesuper cells are arranged end-to-end in pairs to form six rows of supercells, with the rows and the long sides of the super cells orientedparallel to the long sides of the solar module. In other variations,each row of super cells may include three or more super cells. Also, asimilarly configured solar module may include more or fewer rows ofsuper cells than shown in this example. Each super cell in this example(and in several of the following examples) comprises 36 rectangularsolar cells each having a width approximately equal to ⅙ the width of a156 mm square or pseudo square wafer. Any other suitable number ofrectangular solar cells of any other suitable dimensions may also beused. Gap 410 facilitates making electrical contact to front surface endcontacts of super cells 100 along the center line of the solar module.In this example, flexible interconnects 400 positioned adjacent to andrunning parallel to the edge of one short side of the moduleelectrically interconnect the front surface terminal contacts of six ofthe super cells. Similarly, flexible interconnects positioned adjacentto and running parallel to the edge of the other short side of themodule behind the module electrically connect the rear surface terminalcontacts of the other six super cells. Flexible interconnects (not shownin this figure) positioned along gap 410 interconnect each pair of supercells in a row in series and, optionally, extend laterally tointerconnect adjacent rows in parallel. This arrangement electricallyconnects the six rows of super cells in parallel. Optionally, in a firstgroup of super cells the first super cell in each row is electricallyconnected in parallel with the first super cell in each of the otherrows, in a second group of super cells the second super cell iselectrically connected in parallel with the second super cell in each ofthe other rows, and the two groups of super cells are electricallyconnect in series. The later arrangement allows each of the two groupsof super cells to be individually put in parallel with a bypass diode.

Detail A in FIG. 5D identifies the location of a cross-sectional viewshown in FIG. 8A of the interconnection of the rear surface terminalcontacts of super cells along the edge of one short side of the module.Detail B similarly identifies the location of a cross-sectional viewshown in FIG. 8B of the interconnection of the front surface terminalcontacts of super cells along the edge of the other short side of themodule. Detail C identifies the location of a cross-sectional view shownin FIG. 8C of series interconnection of the super cells within a rowalong gap 410.

FIG. 5E shows an example rectangular solar module 370 configuredsimilarly to that of FIG. 5C, except that in this example all of thesolar cells from which the super cells are formed are chevron solarcells having chamfered corners corresponding to corners of pseudo-squarewafers from which the solar cells were separated.

FIG. 5F shows another example rectangular solar module 380 configuredsimilarly to that of FIG. 5C, except that in this example the solarcells from which the super cells are formed comprise a mixture ofchevron and rectangular solar cells arranged to reproduce the shapes ofthe pseudo-square wafers from which they were separated. In the exampleof FIG. 5F, the chevron solar cells may be wider perpendicular to theirlong axes than are the rectangular solar cells to compensate for themissing corners on the chevron cells, so that the chevron solar cellsand the rectangular solar cells have the same active area exposed tosolar radiation during operation of the module and therefore matchedcurrent.

FIG. 5G shows another example rectangular solar module configuredsimilarly to that of FIG. 5E (i.e., including only chevron solar cells)except that in the solar module of FIG. 5G adjacent chevron solar cellsin a super cell are arranged as mirror images of each other so thattheir overlapping edges are of the same length. This maximizes thelength of each overlapping joint, and thereby facilitates heat flowthrough the super cell.

Other configurations of rectangular solar modules may include one ormore rows of super cells formed only from rectangular (non-chamfered)solar cells, and one or more rows of super cells formed only fromchamfered solar cells. For example, a rectangular solar module may beconfigured similarly to that of FIG. 5C, except having the two outerrows of super cells each replaced by a row of super cells formed onlyfrom chamfered solar cells. The chamfered solar cells in those rows maybe arranged in mirror image pairs as shown in FIG. 5G, for example.

In the example solar modules shown in FIGS. 5C-5G, the electric currentalong each row of super cells is about ⅙ of that in a conventional solarmodule of the same area because the rectangular solar cells from whichthe super cells are formed has an active area of about ⅙ that of aconventionally sized solar cell. Because in these examples the six rowsof super cells are electrically connected in parallel, however, theexample solar modules may generate a total electric current equal tothat generated by a conventional solar module of the same area. Thisfacilitates substation of the example solar modules of FIGS. 5C-5G (andother examples described below) for conventional solar modules.

FIG. 6 shows in more detail than FIGS. 5C-5G an example arrangement ofthree rows of super cells interconnected with flexible electricalinterconnects to put the super cells within each row in series with eachother, and to put the rows in parallel with each other. These may bethree rows in the solar module of FIG. 5D, for example. In the exampleof FIG. 6, each super cell 100 has a flexible interconnect 400conductively bonded to its front surface terminal contact, and anotherflexible interconnect conductively bonded to its rear surface terminalcontact. The two super cells within each row are electrically connectedin series by a shared flexible interconnect conductively bonded to thefront surface terminal contact of one super cell and to the rear surfaceterminal contact of the other super cell. Each flexible interconnect ispositioned adjacent to and runs parallel to an end of a super cell towhich it is bonded, and may extend laterally beyond the super cell to beconductively bonded to a flexible interconnect on a super cell in anadjacent row, electrically connecting the adjacent rows in parallel.Dotted lines in FIG. 6 depict portions of the flexible interconnectsthat are hidden from view by overlying portions of the super cells, orportions of the super cells that are hidden from view by overlyingportions of the flexible interconnects.

Flexible interconnects 400 may be conductively bonded to the super cellswith, for example, a mechanically compliant electrically conductivebonding material as described above for use in bonding overlapped solarcells. Optionally, the electrically conductive bonding material may belocated only at discrete positions along the edges of the super cellrather than in a continuous line extending substantially the length ofthe edge of the super cell, to reduce or accommodate stress parallel tothe edges of the super cell arising from mismatch between thecoefficient of thermal expansion of the electrically conductive bondingmaterial or the interconnects and that of the super cell.

Flexible interconnects 400 may be formed from or comprise thin coppersheets, for example. Flexible interconnects 400 may be optionallypatterned or otherwise configured to increase their mechanicalcompliance (flexibility) both perpendicular to and parallel to the edgesof the super cells to reduce or accommodate stress perpendicular andparallel to the edges of the super cells arising from mismatch betweenthe CTE of the interconnect and that of the super cells. Such patterningmay include, for example, slits, slots, or holes. Conductive portions ofinterconnects 400 may have a thickness of, for example, less than about100 microns, less than about 50 microns, less than about 30 microns, orless than about 25 microns to increase the flexibility of theinterconnects. The mechanical compliance of the flexible interconnect,and its bonds to the super cells, should be sufficient for theinterconnected super cells to survive stress arising from CTE mismatchduring the lamination process described in more detail below withrespect to methods of manufacturing shingled solar cell modules, and tosurvive stress arising from CTE mismatch during temperature cyclingtesting between about −40° C. and about 85° C.

Preferably, flexible interconnects 400 exhibit a resistance to currentflow parallel to the ends of the super cells to which they are bonded ofless than or equal to about 0.015 Ohms, less than or equal to about0.012 Ohms, or less than or equal to about 0.01 Ohms.

FIG. 7A shows several example configurations, designated by referencenumerals 400A-400T, that may be suitable for flexible interconnect 400.

As shown in the cross-sectional views of FIGS. 8A-8C, for example, thesolar modules described in this specification typically comprise alaminate structure with super cells and one or more encapsulantmaterials 4101 sandwiched between a transparent front sheet 420 and aback sheet 430. The transparent front sheet may be glass, for example.Optionally, the back sheet may also be transparent, which may allowbifacial operation of the solar module. The back sheet may be a polymersheet, for example. Alternatively, the solar module may be a glass-glassmodule with both the front and back sheets glass.

The cross-sectional view of FIG. 8A (detail A from FIG. 5D) shows anexample of a flexible interconnect 400 conductively bonded to a rearsurface terminal contact of a super cell near the edge of the solarmodule and extending inward beneath the super cell, hidden from viewfrom the front of the solar module. An extra strip of encapsulant may bedisposed between interconnect 400 and the rear surface of the supercell, as illustrated.

The cross-sectional view of FIG. 8B (Detail B from FIG. 5B) shows anexample of a flexible interconnect 400 conductively bonded to a frontsurface terminal contact of a super cell.

The cross-sectional view of FIG. 8C (Detail C from FIG. 5B) shows anexample of a shared flexible interconnect 400 conductively bonded to thefront surface terminal contact of one super cell and to the rear surfaceterminal contact of the other super cell to electrically connect the twosuper cells in series.

Flexible interconnects electrically connected to the front surfaceterminal contact of a super cell may be configured or arranged to occupyonly a narrow width of the front surface of the solar module, which mayfor example be located adjacent an edge of the solar module. The regionof the front surface of the module occupied by such interconnects mayhave a narrow width perpendicular to the edge of the super cell of, forexample, ≦about 10 mm, ≦about 5 mm, or ≦about 3 mm. In the arrangementshown in FIG. 8B, for example, flexible interconnect 400 may beconfigured to extend beyond the end of the super cell by no more thansuch a distance. FIGS. 8D-8G show additional examples of arrangements bywhich a flexible interconnect electrically connected to a front surfaceterminal contact of a super cell may occupy only a narrow width of thefront surface of the module. Such arrangements facilitate efficient useof the front surface area of the module to produce electricity.

FIG. 8D shows a flexible interconnect 400 that is conductively bonded toa terminal front surface contact of a super cell and folded around theedge of the super cell to the rear of the super cell. An insulating film435, which may be pre-coated on flexible interconnect 400, may bedisposed between flexible interconnect 400 and the rear surface of thesuper cell.

FIG. 8E shows a flexible interconnect 400 comprising a thin narrowribbon 440 that is conductively bonded to a terminal front surfacecontact of a super cell and also to a thin wide ribbon 445 that extendsbehind the rear surface of the super cell. An insulating film 435, whichmay be pre-coated on ribbon 445, may be disposed between ribbon 445 andthe rear surface of the super cell.

FIG. 8F shows a flexible interconnect 400 bonded to a terminal frontsurface contact of a super cell and rolled and pressed into a flattenedcoil that occupies only a narrow width of the solar module frontsurface.

FIG. 8G shows a flexible interconnect 400 comprising a thin ribbonsection that is conductively bonded to a terminal front surface contactof a super cell and a thick cross-section portion located adjacent tothe super cell.

In FIGS. 8A-8G, flexible interconnects 400 may extend along the fulllengths of the edges of the super cells (e.g., into the drawing page) asshown in FIG. 6 for example.

Optionally, portions of a flexible interconnect 400 that are otherwisevisible from the front of the module may be covered by a dark film orcoating or otherwise colored to reduce visible contrast between theinterconnect and the super cell, as perceived by a human having normalcolor vision. For example, in FIG. 8C optional black film or coating 425covers portions of the interconnect 400 that would otherwise be visiblefrom the front of the module. Otherwise visible portions of interconnect400 shown in the other figures may be similarly covered or colored.

Conventional solar modules typically include three or more bypassdiodes, with each bypass diode connected in parallel with a seriesconnected group of 18-24 silicon solar cells. This is done to limit theamount of power that may be dissipated as heat in a reverse biased solarcell. A solar cell may become reverse biased, for example, because of adefect, a dirty front surface, or uneven illumination that reduces itsability to pass current generated in the string. Heat generated in asolar cell in reverse bias depends on the voltage across the solar celland the current through the solar cell. If the voltage across thereverse biased solar cell exceeds the breakdown voltage of the solarcell, the heat dissipated in the cell will be equal to the breakdownvoltage times the full current generated in the string. Silicon solarcells typically have a breakdown voltage of 16-30 Volts. Because eachsilicon solar cell produces a voltage of about 0.64 Volts in operation,a string of more than 24 solar cells could produce a voltage across areverse biased solar cell exceeding the breakdown voltage.

In conventional solar modules in which the solar cells are spaced apartfrom each other and interconnected with ribbons, heat is not readilytransported away from a hot solar cell. Consequently, the powerdissipated in a solar cell at breakdown voltage could produce a hot spotin the solar cell that causes significant thermal damage and perhaps afire. In conventional solar modules a bypass diode is therefore requiredfor every group of 18-24 series connected solar cells to insure that nosolar cell in the string can be reverse biased above the breakdownvoltage.

Applicants have discovered that heat is readily transported along asilicon super cell through the thin electrically and thermallyconductive bonds between adjacent overlapping silicon solar cells.Further, the current through a super cell in the solar modules describedherein is typically less than that through a string of conventionalsolar cells, because the super cells described herein are typicallyformed by shingling rectangular solar cells each of which has an activearea less than (for example, ⅙) that of a conventional solar cell.Furthermore, the rectangular aspect ratio of the solar cells typicallyemployed herein provides extended regions of thermal contact betweenadjacent solar cells. As a consequence, less heat is dissipated in asolar cell reverse biased at the breakdown voltage, and the heat readilyspreads through the super cell and the solar module without creating adangerous hot spot. Applicants have therefore recognized that solarmodules formed from super cells as described herein may employ far fewerbypass diodes than conventionally believed to be required.

For example, in some variations of solar modules as described herein asuper cell comprising N>25 solar cells, N≧about 30 solar cells, N≧about50 solar cells, N≧about 70 solar cells, or N≧about 100 solar cells maybe employed with no single solar cell or group of <N solar cells in thesuper cell individually electrically connected in parallel with a bypassdiode. Optionally, a full super cell of these lengths may beelectrically connected in parallel with a single bypass diode.Optionally, super cells of these lengths may be employed without abypass diode.

Several additional and optional design features may make solar modulesemploying super cells as described herein even more tolerant to heatdissipated in a reverse biased solar cell. Referring again to FIGS.8A-8C, encapsulant 4101 may be or comprise a thermoplastic olefin (TPO)polymer, TPO encapsulants are more photo-thermal stable than standardethylene-vinyl acetate (EVA) encapsulants. EVA will brown withtemperature and ultraviolet light and lead to hot spot issues created bycurrent limiting cells. These problems are reduced or avoided with TPOencapsulant. Further, the solar modules may have a glass-glass structurein which both the transparent front sheet 420 and the back sheet 430 areglass. Such a glass-glass enables the solar module to safely operate attemperatures greater than those tolerated by a conventional polymer backsheet. Further still, junction boxes may be mounted on one or more edgesof a solar module, rather than behind the solar module where a junctionbox would add an additional layer of thermal insulation to the solarcells in the module above it.

FIG. 9A shows an example rectangular solar module comprising sixrectangular shingled super cells arranged in six rows extending thelength of the long sides of the solar module. The six super cells areelectrically connected in parallel with each other and with a bypassdiode disposed in a junction box 490 on the rear surface of the solarmodule. Electrical connections between the super cells and the bypassdiode are made through ribbons 450 embedded in the laminate structure ofthe module.

FIG. 9B shows another example rectangular solar module comprising sixrectangular shingled super cells arranged in six rows extending thelength of the long sides of the solar module. The super cells areelectrically connected in parallel with each other. Separate positive490P and negative 490N terminal junction boxes are disposed on the rearsurface of the solar module at opposite ends of the solar module. Thesuper cells are electrically connected in parallel with a bypass diodelocated in one of the junction boxes by an external cable 455 runningbetween the junction boxes.

FIGS. 9C-9D show an example glass-glass rectangular solar modulecomprising six rectangular shingled super cells arranged in six rowsextending the length of the long sides of the solar module in alamination structure comprising glass front and back sheets. The supercells are electrically connected in parallel with each other. Separatepositive 490P and negative 490N terminal junction boxes are mounted onopposite edges of the solar module.

Shingled super cells open up unique opportunities for module layout withrespect to module level power management devices (for example, DC/ACmicro-inverters, DC/DC module power optimizers, voltage intelligence andsmart switches, and related devices). The key feature of module levelpower management systems is power optimization. Super cells as describedand employed herein may produce higher voltages than traditional panels.In addition, super cell module layout may further partition the module.Both higher voltages and increased partitioning create potentialadvantages for power optimization.

FIG. 9E shows one example architecture for module level power managementusing shingled super cells. In this figure an example rectangular solarmodule comprises six rectangular shingled super cells arranged in sixrows extending the length of the long sides of the solar module. Threepairs of super cells are individually connected to a power managementsystem 460, enabling more discrete power optimization of the module.

FIG. 9F shows another example architecture for module level powermanagement using shingled super cells. In this figure an examplerectangular solar module comprises six rectangular shingled super cellsarranged in six rows extending the length of the long sides of the solarmodule. The six super cells are individually connected to a powermanagement system 460, enabling yet more discrete power optimization ofthe module.

FIG. 9G shows another example architecture for module level powermanagement using shingled super cells. In this figure an examplerectangular solar module comprises six or more rectangular shingledsuper cells 998 arranged in six or more rows, where the three or moresuper cells pairs are individually connected to a bypass diode or apower management system 460, to allow yet more discrete poweroptimization of the module.

FIG. 9H shows another example architecture for module level powermanagement using shingled super cells. In this figure an examplerectangular solar module comprises six or more rectangular shingledsuper cells 998 arranged in six or more rows, where each two super cellare connected in series, and all pairs are connected in parallel. Abypass diode or power management system 460 is connected in parallel toall pairs, permitting power optimization of the module.

In some variations, module level power management allows elimination ofall bypass diodes on the solar module while still excluding the risk ofhot spots. This is accomplished by integrating voltage intelligence atthe module level. By monitoring the voltage output of a solar cellcircuit (e.g., one or more super cells) in the solar module, a “smartswitch” power management device can determine if that circuit includesany solar cells in reverse bias. If a reverse biased solar cell isdetected, the power management device can disconnect the correspondingcircuit from the electrical system using, for example, a relay switch orother component. For example, if the voltage of a monitored solar cellcircuit drops below a predetermined threshold (V_(Limit)), then thepower management device will shut off (open circuit) that circuit whileensuring that the module or string of modules remain connected.

In certain embodiments, where a voltage of the circuits drops by morethan a certain percentage or magnitude (e.g., 20% or 10V) from the othercircuits in same solar array, it will be shut off. The electronics willdetect this change based upon inter-module communication.

Implementation of such voltage intelligence may be incorporated intoexisting module level power management solutions (e.g., from EnphaseEnergy Inc., Solaredge Technologies, Inc., Tigo Energy, Inc.) or througha custom circuit design.

One example of how the V_(Limit) threshold voltage may be calculated is:

CellVoc_(@Low Irr & High Temp) ×N _(number of cells in series) −Vrb_(Reverse breakdown voltage) ≦V _(Limit),

where:

-   -   CellVoc_(@Low Irr & High Temp)=open circuit voltage of a cell        working at low irradiation and at high temperature (lowest        expected working Voc);    -   N_(number of cells in series)=a number of cells connected in        series in each super cell monitored.    -   Vrb_(Reverse breakdown voltage)=revered polarity voltage needed        to pass current through a cell.

This approach to module level power management using a smart switch mayallow, for example more than 100 silicon solar cells to be connected inseries within a single module without affecting safety or modulereliability. In addition, such a smart switch can be used to limitstring voltage going to a central inverter. Longer module strings cantherefore be installed without safety or permitting concerns regardingover voltage. The weakest module can be bypassed (switched off) ifstring voltages run up against the limit.

FIGS. 10A, 11A, 12A, 13A, 13B, and 14B described below provideadditional example schematic electrical circuits for solar modulesemploying shingled super cells. FIGS. 10B-1, 10B-2, 11B-1, 11B-2, 11C-1,11C-2, 12B-1, 12B-2, 12C-1, 12C-2, 12C-3, 13C-1, 13C-2, 14C-1, and 14C-2provide example physical layouts corresponding to those schematiccircuits. The description of the physical layouts assumes that the frontsurface end contact of each super cell is of negative polarity and therear surface end contact of each super cell is of positive polarity. Ifinstead the modules employ super cells having front surface end contactsof positive polarity and rear surface end contacts of negative polarity,then the discussion of the physical layouts below may be modified byswapping positive for negative and by reversing the orientation of thebypass diodes. Some of the various buses referred to in the descriptionof these figures may be formed, for example, with interconnects 400described above. Other buses described in these figures may beimplemented, for example, with ribbons embedded in the laminatestructure of solar module or with external cables.

FIG. 10A shows an example schematic electrical circuit for a solarmodule as illustrated in FIG. 5B, in which the solar module includes tenrectangular super cells 100 each of which has a length approximatelyequal to the length of the short sides of the solar module. The supercells are arranged in the solar module with their long sides orientedparallel to the short sides of the module. All of the super cells areelectrically connected in parallel with a bypass diode 480.

FIGS. 10B-1 and 10B-2 show an example physical layout for the solarmodule of FIG. 10A. Bus 485N connects the negative (front surface) endcontacts of super cells 100 to the positive terminal of bypass diode 480in junction box 490 located on the rear surface of the module. Bus 485Pconnects the positive (rear surface) end contacts of super cells 100 tothe negative terminal of bypass diode 480. Bus 485P may lie entirelybehind the super cells. Bus 485N and/or its interconnection to the supercells occupy a portion of the front surface of the module.

FIG. 11A shows an example schematic electrical circuit for a solarmodule as illustrated in FIG. 5A, in which the solar module includestwenty rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module, and the super cells are arranged end-to-end in pairs toform ten rows of super cells. The first super cell in each row isconnected in parallel with the first super cells in the other rows andin parallel with a bypass diode 500. The second super cell in each rowis connected in parallel with the second super cells in the other rowsand in parallel with a bypass diode 510. The two groups of super cellsare connected in series, as are the two bypass diodes.

FIGS. 11B-1 and 11B-2 show an example physical layout for the solarmodule of FIG. 11A. In this layout the first super cell in each row hasits front surface (negative) end contact along a first side of themodule and its rear surface (positive) end contact along the center lineof the module, and the second super cell in each row has its frontsurface (negative) end contact along the center line of the module andits rear surface (positive) end contact along a second side of themodule opposite from the first side. Bus 515N connects the front surface(negative) end contact of the first super cell in each row to thepositive terminal of bypass diode 500. Bus 515P connects the rearsurface (positive) end contact of the second super cell in each row tothe negative terminal of bypass diode 510. Bus 520 connects the rearsurface (positive) end contact of the first super cell in each row andthe front surface (negative) end contact of the second super cell ineach row to the negative terminal of bypass diode 500 and to thepositive terminal of bypass diode 510.

Bus 515P may lie entirely behind the super cells. Bus 515N and/or itsinterconnection to the super cells occupy a portion of the front surfaceof the module. Bus 520 may occupy a portion of the front surface of themodule, requiring a gap 210 as shown in FIG. 5A. Alternatively, bus 520may lie entirely behind the super cells and be electrically connected tothe super cells with hidden interconnects sandwiched between overlappingends of the super cells. In such a case little or no gap 210 isrequired.

FIGS. 11C-1, 11C-2, and 11C-3 show another example physical layout forthe solar module of FIG. 11A. In this layout the first super cell ineach row has its front surface (negative) end contact along a first sideof the module and its rear surface (positive) end contact along thecenter line of the module, and the second super cell in each row has itsrear surface (positive) end contact along the center line of the moduleand its front surface (negative) end contact along a second side of themodule opposite from the first side. Bus 525N connects the front surface(negative) end contact of the first super cell in each row to thepositive terminal of bypass diode 500. Bus 530N connects the frontsurface (negative) end contact of the second cell in each row to thenegative terminal of bypass diode 500 and to the positive terminal ofbypass diode 510. Bus 535P connects the rear surface (positive) endcontact of the first cell in each row to the negative terminal of bypassdiode 500 and to the positive terminal of bypass diode 510. Bus 540Pconnects the rear surface (positive) end contact of the second cell ineach row to the negative terminal of bypass diode 510.

Bus 535P and bus 540P may lie entirely behind the super cells. Bus 525Nand bus 530N and/or their interconnection to the super cells occupy aportion of the front surface of the module.

FIG. 12A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A, in which the solar module includestwenty rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module, and the super cells are arranged end-to-end in pairs toform ten rows of super cells. In the circuit shown in FIG. 12A, thesuper cells are arranged in four groups: in a first group the firstsuper cells of the top five rows are connected in parallel with eachother and with a bypass diode 545, in a second group the second supercells of the top five rows are connected in parallel with each other andwith a bypass diode 505, in a third group the first super cells of thebottom five rows are connected in parallel with each other and with abypass diode 560, and in a fourth group the second super cells of thebottom five rows are connected in parallel with each other and with abypass diode 555. The four groups of super cells are connected in serieswith each other. The four bypass diodes are also in series.

FIGS. 12B-1 and 12B-2 show an example physical layout for the solarmodule of FIG. 12A. In this layout the first group of super cells hasits front surface (negative) end contacts along a first side of themodule and its rear surface (positive) end contacts along the centerline of the module, the second group of super cells has its frontsurface (negative) end contacts along the center line of the module andits rear surface (positive) end contacts along a second side of themodule opposite from the first side, the third group of super cells hasits rear surface (positive) end contacts along the first side of themodule and its front surface (negative) end contacts along the centerline of the module, and the fourth group of super cells has its rearsurface (positive) end contact along the center line of the module andits front surface (negative) end contact along the second side of themodule.

Bus 565N connects the front surface (negative) end contacts of the supercells in the first group of super cells to each other and to thepositive terminal of bypass diode 545. Bus 570 connects the rear surface(positive) end contacts of the super cells in the first group of supercells and the front surface (negative) end contacts of the super cellsin the second group of super cells to each other, to the negativeterminal of bypass diode 545, and to the positive terminal of bypassdiode 550. Bus 575 connects the rear surface (positive) end contacts ofthe super cells in the second group of super cells and the front surface(negative) end contacts of the super cells in the fourth group of supercells to each other, to the negative terminal of bypass diode 550, andto the positive terminal of bypass diode 555. Bus 580 connects the rearsurface (positive) end contacts of the super cells in the fourth groupof super cells and the front surface (negative) end contacts of thesuper cells in the third group of super cells to each other, to thenegative terminal of bypass diode 555, and to the positive terminal ofbypass diode 560. Bus 585P connects the rear surface (positive) endcontacts of the super cells in the third group of super cells to eachother and to the negative terminal of bypass diode 560.

Bus 585P and the portion of bus 575 connecting to the super cells of thesecond group of super cells may lie entirely behind the super cells. Theremaining portion of bus 575 and bus 565N and/or their interconnectionto the super cells occupy a portion of the front surface of the module.

Bus 570 and bus 580 may occupy a portion of the front surface of themodule, requiring a gap 210 as shown in FIG. 5A. Alternatively, they maylie entirely behind the super cells and be electrically connected to thesuper cells with hidden interconnects sandwiched between overlappingends of super cells. In such a case little or no gap 210 is required.

FIGS. 12C-1, 12C-2, and 12C-3 show an alternative physical layout forthe solar module of FIG. 12A. This layout uses two junction boxes 490Aand 490B in place of the single junction box 490 shown in FIGS. 12B-1and 12B-2, but is otherwise equivalent to that of FIGS. 12B-1 and 12B-2.

FIG. 13A shows another example schematic circuit diagram for a solarmodule as illustrated in FIG. 5A, in which the solar module includestwenty rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module, and the super cells are arranged end-to-end in pairs toform ten rows of super cells. In the circuit shown in FIG. 13A, thesuper cells are arranged in four groups: in a first group the firstsuper cells of the top five rows are connected in parallel with eachother, in a second group the second super cells of the top five rows areconnected in parallel with each other, in a third group the first supercells of the bottom five rows are connected in parallel with each other,and in a fourth group the second super cells of the bottom five rows areconnected in parallel with each other. The first group and the secondgroup are connected in series with each other and thus connected are inparallel with a bypass diode 590. The third group and the fourth groupare connected in series with each other and thus connected in parallelwith another bypass diode 595. The first and second groups are connectedin series with the third and fourth groups, and the two bypass diodesare in series as well.

FIGS. 13C-1 and 13C-2 show an example physical layout for the solarmodule of FIG. 13A. In this layout the first group of super cells hasits front surface (negative) end contact along a first side of themodule and its rear surface (positive) end contact along the center lineof the module, the second group of super cells has its front surface(negative) end contact along the center line of the module and its rearsurface (positive) end contact along a second side of the moduleopposite from the first side, the third group of super cells has itsrear surface (positive) end contact along the first side of the moduleand its front surface (negative) end contact along the center line ofthe module, and the fourth group of super cells has its rear surface(positive) end contact along the center line of the module and its frontsurface (negative) end contact along the second side of the module.

Bus 600 connects the front surface (negative) end contacts of the firstgroup of super cells to each other, to the rear surface (positive) endcontacts of the third group of super cells, to the positive terminal ofbypass diode 590, and to the negative terminal of bypass diode 595. Bus605 connects the rear surface (positive) end contacts of the first groupof super cells to each other and to the front surface (negative) endcontacts of the second group of super cells. Bus 610P connects the rearsurface (positive) end contacts of the second group of super cells toeach other and to the negative terminal of bypass diode 590. Bus 615Nconnects the front surface (negative) end contacts of the fourth groupof super cells to each other and to the positive terminal of bypassdiode 595. Bus 620 connects the front surface (negative) end contacts ofthe third group of super cells to each other and to the rear surface(positive) end contacts of the fourth group of super cells.

Bus 610P and the portion of bus 600 connecting to the super cells of thethird group of super cells may lie entirely behind the super cells. Theremaining portion of bus 600 and bus 615N and/or their interconnectionto the super cells occupy a portion of the front surface of the module.

Bus 605 and bus 620 occupy a portion of the front surface of the module,requiring a gap 210 as shown in FIG. 5A. Alternatively, they may lieentirely behind the super cells and be electrically connected to thesuper cells with hidden interconnects sandwiched between overlappingends of super cells. In such a case little or no gap 210 is required.

FIG. 13B shows an example schematic electrical circuit for a solarmodule as illustrated in FIG. 5B, in which the solar module includes tenrectangular super cells 100 each of which has a length approximatelyequal to the length of the short sides of the solar module. The supercells are arranged in the solar module with their long sides orientedparallel to the short sides of the module. In the circuit shown in FIG.13B, the super cells are arranged in two groups: in a first group thetop five super cells are connected in parallel with each other and withbypass diode 590, and in a second group the bottom five super cells areconnected in parallel with each other and with bypass diode 595. The twogroups are connected in series with each other. The bypass diodes arealso connected in series.

The schematic circuit of FIG. 13B differs from that of FIG. 13A byreplacing each row of two super cells in FIG. 13A with a single supercell. Consequently, the physical layout for the solar module of FIG. 13Bmay be as shown in FIGS. 13C-1, 13C-2, and 13C-3, with the omission ofbus 605 and bus 620.

FIG. 14A shows an example rectangular solar module 700 comprisingtwenty-four rectangular super cells 100, each of which has a lengthapproximately equal to one half the length of the short sides of thesolar module. Super cells are arranged end-to-end in pairs to formtwelve rows of super cells, with the rows and the long sides of thesuper cells oriented parallel to the short sides of the solar module.

FIG. 14B shows an example schematic circuit diagram for a solar moduleas illustrated in FIG. 14A. In the circuit shown in FIG. 14B, the supercells are arranged in three groups: in a first group the first supercells of the top eight rows are connected in parallel with each otherand with a bypass diode 705, in a second group the super cells of thebottom four rows are connected in parallel with each other and with abypass diode 710, and in a third group the second super cells of the topeight rows are connected in parallel with each other and with a bypassdiode 715. The three groups of super cells are connected in series. Thethree bypass diodes are also in series.

FIGS. 14C-1 and 14C-2 show an example physical layout for the solarmodule of FIG. 14B. In this layout the first group of super cells hasits front surface (negative) end contacts along a first side of themodule and its rear surface (positive) end contacts along the centerline of the module. In the second group of super cells, the first supercell in each of the bottom four rows has its rear surface (positive) endcontact along the first side of the module and its front surface(negative) end contact along the center line of the module, and thesecond super cell in each of the bottom four rows has its front surface(negative) end contact along the center line of the module and its rearsurface (positive) end contact along a second side of the moduleopposite from the first side. The third group of solar cells has itsrear surface (positive) end contacts along the center line of the moduleand its rear surface (negative) end contacts along the second side ofthe module.

Bus 720N connects the front surface (negative) end contacts of the firstgroup of super cells to each other and to the positive terminal ofbypass diode 705. Bus 725 connects the rear surface (positive) endcontacts of the first group of super cells to the front surface(negative) end contacts of the second group of super cells, to thenegative terminal of bypass diode 705, and to the positive terminal ofbypass diode 710. Bus 730P connects the rear surface (positive) endcontacts of the third group of super cells to each other and to thenegative terminal of bypass diode 715. Bus 735 connects the frontsurface (negative) end contacts of the third group of super cells toeach other, to the rear surface (positive) end contacts of the secondgroup of super cells, to the negative terminal of bypass diode 710, andto the positive terminal of bypass diode 715.

The portion of bus 725 connecting to the super cells of the first groupof super cells, bus 730P, and the portion of bus 735 connecting to thesuper cells of the second group of super cells may lie entirely behindthe super cells. Bus 720N and the remaining portions of bus 725 and bus735 and/or their interconnection to the super cells occupy a portion ofthe front surface of the module.

Some of the examples described above house the bypass diodes in one ormore junction boxes on the rear surface of the solar module. This is notrequired, however. For example, some or all of the bypass diodes may bepositioned in-plane with the super cells around the perimeter of thesolar module or in gaps between super cells, or positioned behind thesuper cells. In such cases the bypass diodes may be disposed in alaminate structure in which the super cells are encapsulated, forexample. The locations of the bypass diodes may thus be decentralizedand removed from the junction boxes, facilitating replacement of acentral junction box comprising both positive and negative moduleterminals with two separate single-terminal junction boxes which may belocated on the rear surface of the solar module near to outer edges ofthe solar module, for example. This approach generally reduces thecurrent path length in ribbon conductors in the solar module and incabling between solar modules, which may both reduce material cost andincrease module power (by reducing resistive power losses).

Referring to FIG. 15, for example, the physical layout for variouselectrical interconnections for a solar module as illustrated in FIG. 5Bhaving the schematic circuit diagram of FIG. 10A may employ a bypassdiode 480 located in the super cell laminate structure and two singleterminal junction boxes 490P and 490N. FIG. 15 may best be appreciatedby comparison to FIGS. 10B-1 and 10B-2. The other module layoutsdescribed above may be similarly modified.

Use of in-laminate bypass diodes as just described may be facilitated bythe use of reduced current (reduced area) rectangular solar cells asdescribed above, because the power dissipated in a forward-biased bypassdiode by the reduced current solar cells may be less than would be thecase for conventionally sized solar cells. Bypass diodes in solarmodules described in this specification may therefore require lessheat-sinking than is conventional, and consequently may be moved out ofa junction box on the rear surface of the module and into the laminate.

A single solar module may include interconnects, other conductors,and/or bypass diodes supporting two or more electrical configurations,for example supporting two or more of the electrical configurationsdescribed above. In such cases a particular configuration for operationof the solar module may be selected from the two or more alternativeswith the use of switches and/or jumpers, for example. The differentconfigurations may put different numbers of super cells in series and/orin parallel to provide different combinations of voltage and currentoutputs from the solar module. Such a solar module may therefore befactory or field configurable to select from two or more differentvoltage and current combinations, for example to select between a highvoltage and low current configuration, and a low voltage and highcurrent configuration.

FIG. 16 shows an example arrangement of a smart switch module levelpower management device 750, as described above, between two solarmodules.

Referring now to FIG. 17, an example method 800 for making solar modulesas disclosed in this specification comprises the following steps. Instep 810, conventionally sized solar cells (e.g., 156 millimeters×156millimeters or 125 millimeters×125 millimeters) are cut and/or cleavedto form narrow rectangular solar cell “strips”. (See also FIGS. 3A-3E)and related description above, for example). The resulting solar cellstrips may optionally be tested and sorted according to theircurrent-voltage performance. Cells with matching or approximatelymatching current-voltage performance may advantageously be used in thesame super cell or in the same row of series connected super cells. Forexample, it may be advantageous that cells connected in series within asuper cell or within a row of super cells produce matching orapproximately matching current under the same illumination.

In step 815 super cells are assembled from the strip solar cells, with aconductive adhesive bonding material disposed between overlappingportions of adjacent solar cells in the super cells. The conductiveadhesive bonding material may be applied, for example, by ink jetprinting or screen printing.

In step 820 heat and pressure are applied to cure or partially cure theconductive adhesive bonding material between the solar cells in thesuper cells. In one variation, as each additional solar cell is added toa super cell the conductive adhesive bonding material between the newlyadded solar cell and its adjacent overlapping solar cell (already partof the super cell) is cured or partially cured, before the next solarcell is added to the super cell. In another variation, more than twosolar cells or all solar cells in a super cell may be positioned in thedesired overlapping manner before the conductive adhesive bondingmaterial is cured or partially cured. The super cells resulting fromthis step may optionally be tested and sorted according to theircurrent-voltage performance. Super cells with matching or approximatelymatching current-voltage performance may advantageously be used in thesame row of super cells or in the same solar module. For example, it maybe advantageous that super cells or rows of super cells electricallyconnected in parallel produce matching or approximately matchingvoltages under the same illumination.

In step 825 the cured or partially cured super cells are arranged andinterconnected in the desired module configuration in a layeredstructured including encapsulant material, a transparent front (sunside) sheet, and a (optionally transparent) back sheet. The layeredstructure may comprise, for example, a first layer of encapsulant on aglass substrate, the interconnected super cells arranged sun-side downon the first layer of encapsulant, a second layer of encapsulant on thelayer of super cells, and a back sheet on the second layer ofencapsulant. Any other suitable arrangement may also be used.

In lamination step 830 heat and pressure are applied to the layeredstructure to form a cured laminate structure.

In one variation of the method of FIG. 17, the conventionally sizedsolar cells are separated into solar cell strips, after which theconductive adhesive bonding material is applied to each individual solarcell strip. In an alternative variation, the conductive adhesive bondingmaterial is applied to the conventionally sized solar cells prior toseparation of the solar cells into solar cell strips.

At curing step 820 the conductive adhesive bonding material may be fullycured, or it may be only partially cured. In the latter case theconductive adhesive bonding material may be initially partially cured atstep 820 sufficiently to ease handling and interconnection of the supercells, and fully cured during the subsequent lamination step 830.

In some variations a super cell 100 assembled as an intermediate productin method 800 comprises a plurality of rectangular solar cells 10arranged with the long sides of adjacent solar cells overlapped andconductively bonded as described above, and interconnects bonded toterminal contacts at opposite ends of the super cell.

FIG. 30A shows an example super cell with electrical interconnectsbonded to its front and rear surface terminal contacts. The electricalinterconnects run parallel to the terminal edges of the super cell andextend laterally beyond the super cell to facilitate electricalinterconnection with an adjacent super cell.

FIG. 30B shows two of the super cells of FIG. 30A interconnected inparallel. Portions of the interconnects that are otherwise visible fromthe front of the module may be covered or colored (e.g., darkened) toreduce visible contrast between the interconnect and the super cells, asperceived by a human having normal color vision. In the exampleillustrated in FIG. 30A, an interconnect 850 is conductively bonded to afront side terminal contact of a first polarity (e.g., + or −) at oneend of the super cell (on the right side of the drawing), and anotherinterconnect 850 is conductively bonded to a back side terminal contactof the opposite polarity at the other end of the super cell (on the leftside of the drawing). Similarly to the other interconnects describedabove, interconnects 850 may be conductively bonded to the super cellwith the same conductive adhesive bonding material used between solarcells, for example, but this is not required. In the illustratedexample, a portion of each interconnect 850 extends beyond the edge ofsuper cell 100 in a direction perpendicular to the long axis of thesuper cell (and parallel to the long axes of solar cells 10). As shownin FIG. 30B, this allows two or more super cells 100 to be positionedside by side, with the interconnects 850 of one super cell overlappingand conductively bonded to corresponding interconnects 850 on theadjacent super cell to electrically interconnect the two super cells inparallel. Several such interconnects 850 interconnected in series asjust described may form a bus for the module. This arrangement may besuitable, for example, when the individual super cell extends the fullwidth or full length of the module (e.g., FIG. 5B). In addition,interconnects 850 may also be used to electrically connect terminalcontacts of two adjacent super cells within a row of super cells inseries. Pairs or longer strings of such interconnected super cellswithin a row may be electrically connected in parallel with similarlyinterconnected super cells in an adjacent row by overlapping andconductively bonding interconnects 850 in one row with interconnects 850in the adjacent row similarly to as shown in FIG. 30B.

Interconnect 850 may be die cut from a conducting sheet, for example,and may be optionally patterned to increase its mechanical complianceboth perpendicular to and parallel to the edge of the super cell toreduce or accommodate stress perpendicular and parallel to the edge ofthe super cell arising from mismatch between the CTE of the interconnectand that of the super cell. Such patterning may include, for example,slits, slots, or holes (not shown). The mechanical compliance ofinterconnect 850, and its bond or bonds to the super cell, should besufficient for the connections to the super cell to survive stressarising from CTE mismatch during the lamination process described inmore detail below. Interconnect 850 may be bonded to the super cellwith, for example, a mechanically compliant electrically conductivebonding material as described above for use in bonding overlapped solarcells. Optionally, the electrically conductive bonding material may belocated only at discrete positions along the edges of the super cellrather than in a continuous line extending substantially the length ofthe edge of the super cell, to reduce or accommodate stress parallel tothe edges of the super cell arising from mismatch between thecoefficient of thermal expansion of the electrically conductive bondingmaterial or the interconnects and that of the super cell.

Interconnect 850 may be cut from a thin copper sheet, for example, andmay be thinner than conventional conductive interconnects when supercells 100 are formed from solar cells having areas smaller than standardsilicon solar cells and therefore operate at lower currents than isconventional. For example, interconnects 850 may be formed from coppersheet having a thickness of about 50 microns to about 300 microns.Interconnects 850 may be sufficiently thin and flexible to fold aroundand behind the edge of the super cell to which they are bonded,similarly to the interconnects described above.

FIGS. 19A-19D show several example arrangements by which heat andpressure may be applied during method 800 to cure or partially cure theconductive adhesive bonding material between adjacent solar cells in thesuper cells. Any other suitable arrangement may also be employed.

In FIG. 19A, heat and localized pressure are applied to cure orpartially cure conductive adhesive bonding material 12 one joint(overlapping region) at a time. The super cell may be supported by asurface 1000 and pressure may be mechanically applied to the joint fromabove with a bar, pin, or other mechanical contact, for example. Heatmay be applied to the joint with hot air (or other hot gas), with aninfrared lamp, or by heating the mechanical contact that applieslocalized pressure to the joint, for example.

In FIG. 19B, the arrangement of FIG. 19A is extended to a batch processthat simultaneously applies heat and localized pressure to multiplejoints in a super cell.

In FIG. 19C, an uncured super cell is sandwiched between release liners1015 and reusable thermoplastic sheets 1020 and positioned on a carrierplate 1010 supported by a surface 1000. The thermoplastic material ofsheets 1020 is selected to melt at the temperature at which the supercells are cured. Release liners 1015 may be formed from fiberglass andPTFE, for example, and do not adhere to the super cell after the curingprocess. Preferably, release liners 1015 are formed from materials thathave a coefficient of thermal expansion matching or substantiallymatching that of the solar cells (e.g., the CTE of silicon). This isbecause if the CTE of the release liners differs too much from that ofthe solar cells, then the solar cells and the release liners willlengthen by different amounts during the curing process, which wouldtend to pull the super cell apart lengthwise at the joints. A vacuumbladder 1005 overlies this arrangement. The uncured super cell is heatedfrom below through surface 1000 and carrier plate 1010, for example, anda vacuum is pulled between bladder 1005 and support surface 1000. As aresult bladder 1005 applies hydrostatic pressure to the super cellthrough the melted thermoplastic sheets 1020.

In FIG. 19D, an uncured super cell is carried by a perforated movingbelt 1025 through an oven 1035 that heats the super cell. A vacuumapplied through perforations in the belt pulls solar cells 10 toward thebelt, thereby applying pressure to the joints between them. Theconductive adhesive bonding material in those joints cures as the supercell passes through the oven. Preferably, perforated belt 1025 is formedfrom materials that have a CTE matching or substantially matching thatof the solar cells (e.g., the CTE of silicon). This is because if theCTE of belt 1025 differs too much from that of the solar cells, then thesolar cells and the belt will lengthen by different amounts in oven1035, which will tend to pull the super cell apart lengthwise at thejoints.

Method 800 of FIG. 17 includes distinct super cell curing and laminationsteps, and produces an intermediate super cell product. In contrast, inmethod 900 shown in FIG. 18 the super cell curing and lamination stepsare combined. In step 910, conventionally sized solar cells (e.g., 156millimeters×156 millimeters or 125 millimeters×125 millimeters) are cutand/or cleaved to form narrow rectangular solar cell strips. Theresulting solar cell strips may optionally be tested and sorted.

In step 915, the solar cell strips are arranged in the desired moduleconfiguration in a layered structured including encapsulant material, atransparent front (sun side) sheet, and a back sheet. The solar cellstrips are arranged as super cells, with an uncured conductive adhesivebonding material disposed between overlapping portions of adjacent solarcells in the super cells. (The conductive adhesive bonding material maybe applied, for example, by ink jet printing or screen printing).Interconnects are arranged to electrically interconnect the uncuredsuper cells in the desired configuration. The layered structure maycomprise, for example, a first layer of encapsulant on a glasssubstrate, the interconnected super cells arranged sun-side down on thefirst layer of encapsulant, a second layer of encapsulant on the layerof super cells, and a back sheet on the second layer of encapsulant. Anyother suitable arrangement may also be used.

In lamination step 920 heat and pressure are applied to the layeredstructure to cure the conductive adhesive bonding material in the supercells and to form a cured laminate structure. Conductive adhesivebonding material used to bond interconnects to the super cells may becured in this step as well.

In one variation of method 900, the conventionally sized solar cells areseparated into solar cell strips, after which the conductive adhesivebonding material is applied to each individual solar cell strips. In analternative variation, the conductive adhesive bonding material isapplied to the conventionally sized solar cells prior to separation ofthe solar cells into solar cell strips. For example, a plurality ofconventionally sized solar cells may be placed on a large template,conductive adhesive bonding material then dispensed on the solar cells,and the solar cells then simultaneously separated into solar cell stripswith a large fixture. The resulting solar cell strips may then betransported as a group and arranged in the desired module configurationas described above.

As noted above, in some variations of method 800 and of method 900 theconductive adhesive bonding material is applied to the conventionallysized solar cells prior to separating the solar cells into solar cellstrips. The conductive adhesive bonding material is uncured (i.e., still“wet”) when the conventionally sized solar cell is separated to form thesolar cell strips. In some of these variations, the conductive adhesivebonding material is applied to a conventionally sized solar cell (e.g.by ink jet or screen printing), then a laser is used to scribe lines onthe solar cell defining the locations at which the solar cell is to becleaved to form the solar cell strips, then the solar cell is cleavedalong the scribe lines. In these variations the laser power and/or thedistance between the scribe lines and the adhesive bonding material maybe selected to avoid incidentally curing or partially curing theconductive adhesive bonding material with heat from the laser. In othervariations, a laser is used to scribe lines on a conventionally sizedsolar cell defining the locations at which the solar cell is to becleaved to form the solar cell strips, then the conductive adhesivebonding material is applied to the solar cell (e.g. by ink jet or screenprinting), then the solar cell is cleaved along the scribe lines. In thelatter variations it may be preferable to accomplish the step ofapplying the conductive adhesive bonding material without incidentallycleaving or breaking the scribed solar cell during this step.

Referring again to FIGS. 20A-20C, FIG. 20A schematically illustrates aside view of an example apparatus 1050 that may be used to cleavescribed solar cells to which conductive adhesive bonding material hasbeen applied. (Scribing and application of conductive adhesive bondingmaterial may have occurred in either order). In this apparatus, ascribed conventionally sized solar cell 45 to which conductive adhesivebonding material has been applied is carried by a perforated moving belt1060 over a curved portion of a vacuum manifold 1070. As solar cell 45passes over the curved portion of the vacuum manifold, a vacuum appliedthrough the perforations in the belt pulls the bottom surface of solarcell 45 against the vacuum manifold and thereby flexes the solar cell.The radius of curvature R of the curved portion of the vacuum manifoldmay be selected so that flexing solar cell 45 in this manner cleaves thesolar cell along the scribe lines. Advantageously, solar cell 45 may becleaved by this method without contacting the top surface of solar cell45 to which the conductive adhesive bonding material has been applied.

If it is preferred for cleaving to begin at one end of a scribe line(i.e., at one edge of solar cell 45), this may be accomplished withapparatus 1050 of FIG. 20A by for example arranging for the scribe linesto be oriented at an angle θ to the vacuum manifold so that for eachscribe line one end reaches the curved portion of the vacuum manifoldbefore the other end. As shown in FIG. 20B, for example, the solar cellsmay be oriented with their scribe lines at an angle to the direction oftravel of the belt and the manifold oriented perpendicularly to thedirection of travel of the belt. As another example, FIG. 20C shows thecells oriented with their scribe lines perpendicular to the direction oftravel of the belt, and the manifold oriented at an angle.

Any other suitable apparatus may also be used to cleave scribed solarcells to which conductive adhesive bonding material has been applied toform strip solar cells with pre-applied conductive adhesive bondingmaterial. Such apparatus may, for example, use rollers to apply pressureto the top surface of the solar cell to which the conductive adhesivebonding material has been applied. In such cases it is preferable thatthe rollers touch the top surface of the solar cell only in regions towhich conductive adhesive bonding material has not been applied.

In some variations, solar modules comprise super cells arranged in rowson a white or otherwise reflective back sheet, so that a portion ofsolar radiation initially unabsorbed by and passing through the solarcells may be reflected by the back sheet back into the solar cells toproduce electricity. The reflective back sheet may be visible throughthe gaps between rows of super cells, which may result in a solar modulethat appears to have rows of parallel bright (e.g., white) lines runningacross its front surface. Referring to FIG. 5B, for example, theparallel dark lines running between the rows of super cells 100 mayappear as white lines if super cells 100 are arranged on a white backsheet. This may be aesthetically displeasing for some uses of the solarmodules, for example on roof tops.

Referring to FIG. 21, to improve the aesthetic appearance of the solarmodule, some variations employ a white back sheet 1100 comprising darkstripes 1105 located in positions corresponding to the gaps between rowsof the super cells to be arranged on the back sheet. Stripes 1105 aresufficiently wide that the white portions of the back sheet are notvisible through gaps between the rows of super cells in the assembledmodule. This reduces the visual contrast between the super cells and theback sheet, as perceived by a human having normal color vision. Theresulting module includes a white back sheet but may have a frontsurface similar in appearance to that of the modules illustrated inFIGS. 5A-5B, for example. Dark stripes 1105 may be produced with lengthsof dark tape, for example, or in any other suitable manner.

As previously mentioned, shading of individual cells within solarmodules can create ‘hotspots’, wherein power of the non-shaded cells isdissipated in the shaded cell. This dissipated power creates localizedtemperature spikes that can degrade the modules.

To minimize the potential severity of these hotspots, bypass diodes areconventionally inserted as part of the module. The maximal number ofcells between bypass diodes is set to limit the max temperature of themodule and prevent irreversible damage on the module. Standard layoutsfor silicon cells may utilize a bypass diode every 20 or 24 cells, anumber that is determined by the typical break down voltage of siliconcells. In certain embodiments, the breakdown voltage may lie in rangebetween about 10-50V. In certain embodiments, the breakdown voltage maybe about 10V, about 15V, about 20V, about 25V, about 30V, or about 35V.

According to embodiments, the shingling of strips of cut solar cellswith thin thermally conductive adhesives, improves the thermal contactbetween solar cells. This enhanced thermal contact allows higher degreeof thermal spreading than traditional interconnection technologies. Sucha thermal heat spreading design based on shingling allows longer stringsof solar cells to be used than the twenty-four (or fewer) solar cellsper bypass diode to which conventional designs are restricted. Suchrelaxation in the requirement for frequent bypass diodes according tothe thermal spreading facilitated by shingling according to embodiments,may offer one or more benefits. For example, it allows for the creationof module layouts of a variety of solar cell string lengths, unhinderedby a need to provide for a large number of bypass diodes.

According to embodiments, thermal spreading is achieved by maintaining aphysical and thermal bond with the adjacent cell. This allows foradequate heat dissipation though the bonded joint.

In certain embodiments this joint is maintained at a thickness of about200 micrometers or less, and runs the length of the solar cell in asegmented pattern. Depending upon the embodiment, the joint may have athickness of about 200 micrometers or less, of about 150 micrometers orless, of about 125 micrometers or less, of about 100 micrometers orless, of about 90 micrometers or less, of about 80 micrometers or less,of about 70 micrometers or less, of about 50 micrometers, or less, or ofabout 25 micrometers or less.

An accurate adhesive cure processing may be important to ensuring that areliable joint is maintained while a thickness is reduced in order topromote thermal spreading between bonded cells.

Being allowed to run longer strings (e.g., more than 24 cells) affordsflexibility in the design of solar cells and modules. For example,certain embodiments may utilize strings of cut solar cells that areassembled in a shingled manner. Such configurations may utilizesignificantly more cells per module than a conventional module.

Absent the thermal spreading property, a bypass diode would be neededevery 24 cells. Where the solar cells are cut by ⅙, the bypass diodesper module would be 6 times the conventional module (comprises of 3uncut cells), adding up to a total of 18 diodes. Thus thermal spreadingaffords a significant reduction in the number of bypass diodes.

Moreover for every bypass diode, bypass circuitry is needed to completethe bypass electrical path. Each diode requires two interconnectionspoints and conductor routing to connect them to such interconnectionpoints. This creates a complicated circuit, contributing significantexpense over standard layout costs associated with assembling a solarmodule.

By contrast, thermal spreading technology requires only one or even nobypass diodes per module. Such a configuration streamlines a moduleassembly process, allowing simple automation tools to perform the layoutmanufacturing steps.

Avoiding the need to bypass protect every 24 cells thus renders the cellmodule easier to manufacture. Complex tap-outs in the middle of themodule and long parallel connections for bypass circuitry, are avoided.This thermal spreading is implemented by creating long shingled stripsof cells running a width and/or length of the module.

In addition to providing thermal heat spreading, shingling according toembodiments also allows improved hotspot performance by reducing amagnitude of current dissipated in a solar cell. Specifically, during ahot spot condition the amount of current dissipated in a solar cell isdependent upon cell area.

Since shingling may cut cells to smaller areas, an amount of currentpassing through one cell in a hot spot condition is a function of thecut dimensions. During a hot spot condition, the current passes throughthe lowest resistance path which is usually a cell level defectinterface or grain boundary. Reducing this current is a benefit andminimizes reliability risk failure under hot spot conditions.

FIG. 22A shows a plan view of a conventional module 2200 utilizingtraditional ribbon connections 2201, under hot spot conditions. Here,shading 2202 on one cell 2204 results in heat being localized to thatsingle cell.

By contrast, FIG. 22B shows a plan view of a module utilizing thermalspreading, also under hot spot conditions. Here, shading 2250 on cell2252 generates heat within that cell. This heat, however, is spread toother electrically and thermally bonded cells 2254 within the module2256.

It is further noted that the benefit of reduction in dissipated currentis multiplied for multi-crystalline solar cells. Such multi-crystallinecells are known to perform poorly under hot spot conditions owing to ahigh level of defect interfaces.

As indicated above, particular embodiments may employ shingling ofchamfered cut cells. In such cases, there is a heat spreading advantageto mirror, along the bond line between each cell with the adjacent cell.

This maximizes the bond length of each overlapping joint. Since the bondjoint is major interface for cell-to-cell heat spreading, maximizingthis length may ensure the optimum heat spreading is obtained.

FIG. 23A shows one example of a super cell string layout 2300 withchamfered cells 2302. In this configuration, the chamfered cells areoriented in a same direction, and thus all the bonded joints conductionpaths are the same (125 mm).

Shading 2306 on one cell 2304 results in reverse biasing of that cell.Heat is spread to with adjacent cells. Unbonded ends 2304 a of thechamfered cell becomes hottest due to a longer conduction length to thenext cell.

FIG. 23B shows another example of a super cell string layout 2350 withchamfered cells 2352. In this configuration, the chamfered cells areoriented in different directions, with some of the long edges of thechamfered cells facing each other. This results in bonded jointconduction paths of two lengths: 125 mm and 156 mm.

Where a cell 2354 experiences shading 2356, the configuration of FIG.23B exhibits improved thermal spreading along the longer bond length.FIG. 23B thus shows that the thermal spreading in a super cell withchamfered cells facing each other.

The above discussion has focused upon assembling a plurality of solarcells (which may be cut solar cells) in a shingled manner on a commonsubstrate. This results in the formation of a module having a singleelectrical interconnect-junction box (or j-box).

In order to gather a sufficient amount of solar energy to be useful,however, an installation typically comprises a number of such modulesthat are themselves assembled together. According to embodiments, aplurality of solar cell modules may also be assembled in a shingledmanner to increase the area efficiency of an array.

In particular embodiments, a module may feature a top conductive ribbonfacing a direction of solar energy, and a bottom conductive ribbonfacing away from the direction of solar energy.

The bottom ribbon is buried beneath the cells. Thus, it does not blockincoming light and adversely impact an area efficiency of the module. Bycontrast, the top ribbon is exposed and can block the incoming light andadversely impact efficiency.

According to embodiments the modules themselves can be shingled, suchthat the top ribbon is covered by the neighboring module. FIG. 24 showsa simplified cross-sectional view of such an arrangement 2400, where anend portion 2401 of an adjacent module 2402, serves to overlap the topribbon 2404 of an instant module 2406. Each module itself comprises aplurality of shingled solar cells 2407.

The bottom ribbon 2408 of the instant module 2406 is buried. It islocated on an elevated side of the instant shingled module in order tooverlap the next adjacent shingled module.

This shingled module configuration could also provide for additionalarea on the module for other elements, without adversely impacting afinal exposed area of the module array. Examples of module elements thatmay be positioned in overlapping regions can include but are not limitedto, junction boxes (j-boxes) 2410 and/or bus ribbons.

FIG. 25 shows another embodiment of a shingled module configuration2500. Here, j-boxes 2502, 2504 of the respective adjacent shingledmodules 2506 and 2508 are in a mating arrangement 2510 in order toachieve electrical connection between them. This simplifies theconfiguration of the array of shingled modules by eliminating wiring.

In certain embodiments, the j-boxes could be reinforced and/or combinedwith additional structural standoffs. Such a configuration could createan integrated tilted module roof mount rack solution, wherein adimension of the junction box determines a tilt. Such an implementationmay be particularly useful where an array of shingled modules is mountedon a flat roof.

Where the modules comprise a glass substrate and a glass cover(glass-glass modules), the modules could be used without additionalframe members by shortening an overall module length (and hence anexposed length L resulting from the shingling). Such shortening wouldallow the modules of the tiled array to survive expected physical loads(e.g., a 5400 Pa snow load limit), without fracturing under the strain.

It is emphasized that the use of super cell structures comprising aplurality of individual solar cells assembled in a shingled manner,readily accommodates changing the length of the module to meet aspecific length dictated by physical load and other requirements.

FIG. 26 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of the front (sunside) surface terminal electrical contacts of a shingled super cell to ajunction box on the rear side of the module. The front surface terminalcontacts of the shingled super cell may be located adjacent to an edgeof the module.

FIG. 26 shows the use of a flexible interconnect 400 to electricallycontact a front surface end contact of a super cell 100. In theillustrated example, flexible interconnect 400 comprises a ribbonportion 9400A running parallel and adjacent to an end of the super cell100 and fingers 9400B extending perpendicularly to the ribbon portion tocontact the front surface metallization pattern (not shown) of the endsolar cell in the super cell, to which they are conductively bonded. Aribbon conductor 9410 conductively bonded to interconnect 9400 passesbehind super cell 100 to electrically connect interconnect 9400 toelectrical components (e.g., bypass diodes and/or module terminals in ajunction box) on the rear surface of the solar module of which the supercell is a part. An insulating film 9420 may be disposed betweenconductor 9410 and the edge and rear surface of super cell 100 toelectrically insulate ribbon conductor 9410 from super cell 100.

Interconnect 400 may optionally fold around the edge of the super cellso that ribbon portion 9400A lies behind or partially behind the supercell. In such cases an electrically insulating layer is typicallyprovided between interconnect 400 and the edge and rear surfaces ofsuper cell 100.

Interconnect 400 may be die cut from a conducting sheet, for example,and may be optionally patterned to increase its mechanical complianceboth perpendicular to and parallel to the edge of the super cell toreduce or accommodate stress perpendicular and parallel to the edge ofthe super cell arising from mismatch between the CTE of the interconnectand that of the super cell. Such patterning may include, for example,slits, slots, or holes (not shown). The mechanical compliance ofinterconnect 400, and its bond to the super cell, should be sufficientfor the connection to the super cell to survive stress arising from CTEmismatch during the lamination process described in more detail below.Interconnect 400 may be bonded to the super cell with, for example, amechanically compliant electrically conductive bonding material asdescribed above for use in bonding overlapped solar cells. Optionally,the electrically conductive bonding material may be located only atdiscrete positions along the edge of the super cell (e.g., correspondingto the locations of discrete contact pads on the end solar cell) ratherthan in a continuous line extending substantially the length of the edgeof the super cell, to reduce or accommodate stress parallel to the edgeof the super cell arising from mismatch between the coefficient ofthermal expansion of the electrically conductive bonding material or theinterconnect and that of the super cell.

Interconnect 400 may be cut from a thin copper sheet, for example, andmay be thinner than conventional conductive interconnects when supercells 100 are formed from solar cells having areas smaller than standardsilicon solar cells and therefore operate at lower currents than isconventional. For example, interconnects 400 may be formed from coppersheet having a thickness of about 50 microns to about 300 microns. Aninterconnect 400 may be sufficiently thin to accommodate stressperpendicular and parallel to the edge of the super cell arising frommismatch between the CTE of the interconnect and that of the super celleven without being patterned as described above. Ribbon conductor 9410may be formed from copper, for example.

FIG. 27 shows a diagram of the rear (shaded) surface of a solar moduleillustrating an example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module. The front surfaceterminal contacts of the shingled super cells may be located adjacent toan edge of the module.

FIG. 27 shows the use of two flexible interconnects 400, as justdescribed, to make electrical contact to front surface terminal contactsof two adjacent super cells 100. A bus 9430 running parallel andadjacent to ends of the super cells 100 is conductively bonded to thetwo flexible interconnects to electrically connect the super cells inparallel. This scheme can be extended to interconnect additional supercells 100 in parallel, as desired. Bus 9430 may be formed from copperribbon, for example.

Similarly to as described above with respect to FIG. 26, interconnects400 and bus 9430 may optionally fold around the edge of the super cellsso that ribbon portions 9400A and bus 9430 lie behind or partiallybehind the super cells. In such cases an electrically insulating layeris typically provided between interconnects 400 and the edge and rearsurfaces of super cells 100 and between bus 9430 and the edge and rearsurfaces of super cells 100.

FIG. 28 shows a diagram of the rear (shaded) surface of a solar moduleillustrating another example electrical interconnection of two or moreshingled super cells in parallel, with the front (sun side) surfaceterminal electrical contacts of the super cells connected to each otherand to a junction box on the rear side of the module. The front surfaceterminal contacts of the shingled super cells may be located adjacent toan edge of the module.

FIG. 28 shows the use of another example flexible interconnect 9440 toelectrically contact a front surface end contact of a super cell 100. Inthis example, flexible interconnect 9440 comprises a ribbon portion9440A running parallel and adjacent to an end of the super cell 100,fingers 9440B extending perpendicularly to the ribbon portion to contactthe front surface metallization pattern (not shown) of the end solarcell in the super cell, to which they are conductively bonded, andfingers 9440C extending perpendicularly to the ribbon portion and behindthe super cell. Fingers 9440C are conductively bonded to a bus 9450. Bus9450 runs parallel and adjacent to the end of super cell 100 along therear surface of super cell 100, and may extend to overlap adjacent supercells to which it may be similarly electrically connected, therebyconnecting the super cells in parallel. Ribbon conductor 9410conductively bonded to bus 9450 electrically interconnects the supercells to electrical components (e.g., bypass diodes and/or moduleterminals in a junction box) on the rear surface of the solar module.Electrically insulating films 9420 may be provided between fingers 9440Cand the edge and rear surfaces of super cell 100, between bus 9450 andthe rear surface of super cell 100, and between ribbon conductor 9410and the rear surface of super cell 100.

Interconnect 9440 may be die cut from a conducting sheet, for example,and may be optionally patterned to increase its mechanical complianceboth perpendicular to and parallel to the edge of the super cell toreduce or accommodate stress perpendicular and parallel to the edge ofthe super cell arising from mismatch between the CTE of the interconnectand that of the super cell. Such patterning may include, for example,slits, slots, or holes (not shown). The mechanical compliance ofinterconnect 9440, and its bond to the super cell, should be sufficientfor the connection to the super cell to survive stress arising from CTEmismatch during the lamination process described in more detail below.Interconnect 9440 may be bonded to the super cell with, for example, amechanically compliant electrically conductive bonding material asdescribed above for use in bonding overlapped solar cells. Optionally,the electrically conductive bonding material may be located only atdiscrete positions along the edge of the super cell (e.g., correspondingto the locations of discrete contact pads on the end solar cell) ratherthan in a continuous line extending substantially the length of the edgeof the super cell, to reduce or accommodate stress parallel to the edgeof the super cell arising from mismatch between the coefficient ofthermal expansion of the electrically conductive bonding material or theinterconnect and that of the super cell.

Interconnect 9440 may be cut from a thin copper sheet, for example, andmay be thinner than conventional conductive interconnects when supercells 100 are formed from solar cells having areas smaller than standardsilicon solar cells and therefore operate at lower currents than isconventional. For example, interconnects 9440 may be formed from coppersheet having a thickness of about 50 microns to about 300 microns. Aninterconnect 9440 may be sufficiently thin to accommodate stressperpendicular and parallel to the edge of the super cell arising frommismatch between the CTE of the interconnect and that of the super celleven without being patterned as described above. Bus 9450 may be formedfrom copper ribbon, for example.

Fingers 9440C may be bonded to bus 9450 after fingers 9440B are bondedto the front surface of super cell 100. In such cases, fingers 9440C maybe bent away from the rear surface of super cell 100, for exampleperpendicularly to super cell 100, when they are bonded to bus 9450.Afterward, fingers 9440C may be bent to run along the rear surface ofsuper cell 100 as shown in FIG. 28.

FIG. 29 shows fragmentary cross-sectional and perspective diagrams oftwo super cells illustrating the use of a flexible interconnectsandwiched between overlapping ends of adjacent super cells toelectrically connect the super cells in series and to provide anelectrical connection to a junction box. FIG. 29A shows an enlarged viewof an area of interest in FIG. 29.

FIG. 29 and FIG. 29A show the use of an example flexible interconnect2960 partially sandwiched between and electrically interconnecting theoverlapping ends of two super cells 100 to provide an electricalconnection to the front surface end contact of one of the super cellsand to the rear surface end contact of the other super cell, therebyinterconnecting the super cells in series. In the illustrated example,interconnect 2960 is hidden from view from the front of the solar moduleby the upper of the two overlapping solar cells. In another variation,the adjacent ends of the two super cells do not overlap and the portionof interconnect 2960 connected to the front surface end contact of oneof the two super cells may be visible from the front surface of thesolar module. Optionally, in such variations the portion of theinterconnect that is otherwise visible from the front of the module maybe covered or colored (e.g., darkened) to reduce visible contrastbetween the interconnect and the super cells, as perceived by a humanhaving normal color vision. Interconnect 2960 may extend parallel to theadjacent edges of the two super cells beyond the side edges of the supercells to electrically connect the pair of super cells in parallel with asimilarly arranged pair of super cells in an adjacent row.

A ribbon conductor 2970 may be conductively bonded to interconnect 2960as shown to electrically connect the adjacent ends of the two supercells to electrical components (e.g., bypass diodes and/or moduleterminals in a junction box) on the rear surface of the solar module. Inanother variation (not shown) a ribbon conductor 2970 may beelectrically connected to the rear surface contact of one of theoverlapping super cells away from their overlapping ends, instead ofbeing conductively bonded to an interconnect 2960. That configurationmay also provide a hidden tap to one or more bypass diodes or otherelectrical components on the rear surface of the solar module.

Interconnect 2960 may be optionally die cut from a conducting sheet, forexample, and may be optionally patterned to increase its mechanicalcompliance both perpendicular to and parallel to the edges of the supercells to reduce or accommodate stress perpendicular and parallel to theedges of the super cells arising from mismatch between the CTE of theinterconnect and that of the super cells. Such patterning may include,for example, slits, slots (as shown), or holes. The mechanicalcompliance of the flexible interconnect, and its bonds to the supercells, should be sufficient for the interconnected super cells tosurvive stress arising from CTE mismatch during the lamination processdescribed in more detail below. The flexible interconnect may be bondedto the super cells with, for example, a mechanically compliantelectrically conductive bonding material as described above for use inbonding overlapped solar cells. Optionally, the electrically conductivebonding material may be located only at discrete positions along theedges of the super cells rather than in a continuous line extendingsubstantially the length of the edge of the super cells, to reduce oraccommodate stress parallel to the edge of the super cells arising frommismatch between the coefficient of thermal expansion of theelectrically conductive bonding material or the interconnect and that ofthe super cells. Interconnect 2960 may be cut from a thin copper sheet,for example.

Embodiments may include one or more features described in the followingU.S. Patent Publication documents: U.S. Patent Publication No.2014/0124013; and U.S. Patent Publication No. 2014/0124014, both ofwhich are incorporated by reference in their entireties herein for allpurposes.

This specification discloses high-efficiency solar modules comprisingsilicon solar cells arranged in a shingled manner and electricallyconnected in series to form super cells, with the super cells arrangedin physically parallel rows in the solar module. The super cells mayhave lengths spanning essentially the full length or width of the solarmodule, for example, or two or more super cells may be arrangedend-to-end in a row. This arrangement hides solar cell-to-solar cellelectrical interconnections, and may therefore be used to create avisually appealing solar module with little to no contrast betweenadjacent series connected solar cells.

A super cell may comprise any number of solar cells, including in someembodiments at least nineteen solar cells and in certain embodimentsgreater than or equal to 100 silicon solar cells, for example.Electrical contacts at intermediate locations along a super cell may bedesired to electrically segment the super cell into two or more seriesconnected segments while maintaining a physically continuous super cell.This specification discloses arrangements in which such electricalconnections are made to back surface contact pads of one or more siliconsolar cells in the super cell to provide electrical tapping points thatare hidden from view from the front of the solar module, and hencereferred to herein as “hidden taps”. The hidden tap is the electricalconnection between the back of the solar cell and a conductiveinterconnect.

This specification also discloses the use of flexible interconnects toelectrically interconnect front surface super cell terminal contactpads, rear surface super cell terminal contact pads, or hidden tapcontact pads to other solar cells or to other electrical components inthe solar module.

In addition, this specification discloses the use of an electricallyconductive adhesive to directly bond adjacent solar cells to each otherin a super cell to provide mechanically compliant electricallyconductive bonds that accommodate a mismatch in thermal expansionbetween the super cells and a glass front sheet of the solar module, incombination with the use of an electrically conductive adhesive to bondflexible interconnects to the super cells with mechanically stiff bondsthat force the flexible interconnects to accommodate a mismatch inthermal expansion between flexible interconnects and the super cells.This avoids damage to the solar module that may otherwise occur as aresult of thermal cycling of the solar module.

As further described below, electrical connections to hidden tap contactpads may be used to electrically connect segments of a super cell inparallel with corresponding segments of one or more super cells inadjacent rows, and/or to provide electrical connections to the solarmodule circuit for various applications including but not limited topower optimization (e.g., bypass diodes, AC/DC micro-inverters, DC/DCconverters) and reliability applications.

Use of hidden taps as just described may further enhance the aestheticappearance of the solar module by providing in combination with thehidden cell-to-cell connections a substantially all black appearance forthe solar module, and may also increase the efficiency of the solarmodule by allowing a larger portion of the surface area of the module tobe filled by the active areas of the solar cells.

Turning now to the figures for a more detailed understanding of thesolar modules described in this specification, FIG. 1 shows across-sectional view of a string of series-connected solar cells 10arranged in a shingled manner with the ends of adjacent solar cellsoverlapping and electrically connected to form a super cell 100. Eachsolar cell 10 comprises a semiconductor diode structure and electricalcontacts to the semiconductor diode structure by which electric currentgenerated in solar cell 10 when it is illuminated by light may beprovided to an external load.

In the examples described in this specification, each solar cell 10 is arectangular crystalline silicon solar cell having front (sun side)surface and rear (shaded side) surface metallization patterns providingelectrical contact to opposite sides of an n-p junction, the frontsurface metallization pattern is disposed on a semiconductor layer ofn-type conductivity, and the rear surface metallization pattern isdisposed on a semiconductor layer of p-type conductivity. However, othermaterial systems, diode structures, physical dimensions, or electricalcontact arrangements may be used if suitable. For example, the front(sun side) surface metallization pattern may be disposed on asemiconductor layer of p-type conductivity, and the rear (shaded side)surface metallization pattern disposed on a semiconductor layer ofn-type conductivity.

Referring again to FIG. 1, in super cell 100 adjacent solar cells 10 areconductively bonded directly to each other in the region in which theyoverlap by an electrically conducting bonding material that electricallyconnects the front surface metallization pattern of one solar cell tothe rear surface metallization pattern of the adjacent solar cell.Suitable electrically conducting bonding materials may include, forexample, electrically conducting adhesives and electrically conductingadhesive films and adhesive tapes, and conventional solders.

FIGS. 31AA and 31A show the use of an example flexible interconnect 3160partially sandwiched between and electrically interconnecting theoverlapping ends of two super cells 100 to provide an electricalconnection to the front surface end contact of one of the super cellsand to the rear surface end contact of the other super cell, therebyinterconnecting the super cells in series. In the illustrated example,interconnect 3160 is hidden from view from the front of the solar moduleby the upper of the two overlapping solar cells. In another variation,the adjacent ends of the two super cells do not overlap and the portionof interconnect 3160 connected to the front surface end contact of oneof the two super cells may be visible from the front surface of thesolar module. Optionally, in such variations the portion of theinterconnect that is otherwise visible from the front of the module maybe covered or colored (e.g., darkened) to reduce visible contrastbetween the interconnect and the super cells, as perceived by a humanhaving normal color vision. Interconnect 3160 may extend parallel to theadjacent edges of the two super cells beyond the side edges of the supercells to electrically connect the pair of super cells in parallel with asimilarly arranged pair of super cells in an adjacent row.

A ribbon conductor 3170 may be conductively bonded to interconnect 3160as shown to electrically connect the adjacent ends of the two supercells to electrical components (e.g., bypass diodes and/or moduleterminals in a junction box) on the rear surface of the solar module. Inanother variation (not shown) a ribbon conductor 3170 may beelectrically connected to the rear surface contact of one of theoverlapping super cells away from their overlapping ends, instead ofbeing conductively bonded to an interconnect 3160. That configurationmay also provide a hidden tap to one or more bypass diodes or otherelectrical components on the rear surface of the solar module.

FIG. 2 shows an example rectangular solar module 200 comprising sixrectangular super cells 100, each of which has a length approximatelyequal to the length of the long sides of the solar module. The supercells are arranged as six parallel rows with their long sides orientedparallel to the long sides of the module. A similarly configured solarmodule may include more or fewer rows of such side-length super cellsthan shown in this example. In other variations the super cells may eachhave a length approximately equal to the length of a short side of arectangular solar module, and be arranged in parallel rows with theirlong sides oriented parallel to the short sides of the module. In yetother arrangements each row may comprise two or more super cellselectrically interconnected in series. The modules may have shorts sideshaving a length, for example, of about 1 meter and long sides having alength, for example, of about 1.5 to about 2.0 meters. Any othersuitable shapes (e.g., square) and dimensions for the solar modules mayalso be used.

Each super cell in this example comprises 72 rectangular solar cellseach having a width approximately equal to ⅙ the width of a 156 mmsquare or pseudo square wafer. Any other suitable number of rectangularsolar cells of any other suitable dimensions may also be used.

Solar cells having long and narrow aspect ratios and areas less thanthat of a standard 156 mm×156 mm solar cell, as illustrated, may beadvantageously employed to reduce I²R resistive power losses in thesolar cell modules disclosed in this specification. In particular, thereduced area of solar cells 10 compared to standard size silicon solarcells decreases the current produced in the solar cell, directlyreducing resistive power loss in the solar cell and in a seriesconnected string of such solar cells.

A hidden tap to the back surface of a super cell may be made, forexample, using an electrical interconnect conductively bonded to one ormore hidden tap contact pads located in only an edge portion of the backsurface metallization pattern of the solar cell. Alternatively, a hiddentap may be made using an interconnect that runs substantially the fulllength of the solar cell (perpendicular to the long axis of the supercell) and is conductively bonded to a plurality of hidden tap contactpads distributed along the length of the solar cell in the back surfacemetallization pattern.

FIG. 31A shows an example solar cell back surface metallization pattern3300 suitable for use with edge-connected hidden taps. The metallizationpattern comprises a continuous aluminum electrical contact 3310, aplurality of silver contact pads 3315 arranged parallel to and adjacentthe edge of a long side of the back surface of the solar cell, andsilver hidden tap contact pads 3320 each arranged parallel to anadjacent edge of one of the short sides of the back surface of the solarcell. When the solar cell is arranged in a super cell, contact pads 3315are overlapped by and directly bonded to the front surface of anadjacent rectangular solar cell. An interconnect may be conductivelybonded to one or the other of hidden tap contact pads 3320 to provide ahidden tap to the super cell. (Two such interconnects may be employed toprovide two hidden taps, if desired).

In the arrangement shown in FIG. 31A, current flow to the hidden tap isthrough the back surface cell metallization generally parallel to thelong sides of the solar cell to the interconnect aggregation point(contact 3320). To facilitate current flow along this path, the backsurface metallization sheet resistance is preferably less than or equalto about 5 Ohms per square, or less than or equal to about 2.5 Ohms persquare.

FIG. 31B shows another example solar cell back surface metallizationpattern 3301 suitable for use with hidden taps employing a bus-likeinterconnect along the length of the back surface of a solar cell. Themetallization pattern comprises a continuous aluminum electrical contact3310, a plurality of silver contact pads 3315 arranged parallel to andadjacent the edge of a long side of the back surface of the solar cell,and a plurality of silver hidden tap contact pads 3325 arranged in a rowparallel to the long sides of the solar cell and approximately centeredon the back surface of the solar cell. An interconnect runningsubstantially the full length of the solar cell may be conductivelybonded to hidden tap contact pads 3325 to provide a hidden tap to thesuper cell. Current flow to the hidden tap is primarily through thebus-like interconnect, making the conductivity of the back surfacemetallization pattern less important to the hidden tap.

The location and number of hidden tap contact pads to which the hiddentap interconnect is bonded on the back surface of a solar cell affectsthe length of the current path through the back surface metallization ofthe solar cell, the hidden tap contact pads, and the interconnect.Consequently the arrangement of the hidden tap contact pads may beselected to minimize the resistance to current collection in the currentpath to and through the hidden tap interconnect. In addition to theconfigurations shown in FIGS. 31A-31B (and FIG. 31C discussed below),suitable hidden tap contact pad arrangements may include for example atwo dimensional array, and a row running perpendicular to the long axisof the solar cell. In the latter case the row of hidden tap contact padsmay be located adjacent a short edge of the first solar cell, forexample.

FIG. 31C shows another example solar cell back surface metallizationpattern 3303 suitable for use either with edge-connected hidden taps orhidden taps employing a bus-like interconnect along the length of theback surface of a solar cell. The metallization pattern comprises acontinuous copper contact pad 3315 arranged parallel to and adjacent theedge of a long side of the back surface of the solar cell, a pluralityof copper fingers 3317 connected to and extending perpendicularly fromcontact pad 3315, and a continuous copper bus hidden tap contact pad3325 running parallel to the long sides of the solar cell andapproximately centered on the back surface of the solar cell. Anedge-connected interconnect may be bonded to an end portion of copperbus 3325 to provide a hidden tap to the super cell. (Two suchinterconnects may be employed at either end of copper bus 3325 toprovide two hidden taps, if desired). Alternatively, an interconnectrunning substantially the full length of the solar cell may beconductively bonded to copper bus 3325 to provide a hidden tap to thesuper cell.

The interconnect employed to form the hidden tap may be bonded to thehidden tap contact pad in the back surface metallization pattern bysoldering, welding, conductive adhesive, or in any other suitablemanner. For metallization patterns employing silver pads as illustratedin FIGS. 31A-31B, the interconnect may be formed for example fromtin-coated copper. Another approach is to make the hidden tap directlyto aluminum back surface contact 3310 with an aluminum conductor formingan aluminum to aluminum bond, which may be formed for example byelectrical or laser welding, soldering, or conductive adhesive. Incertain embodiments, the contacts may comprise tin. In cases as justdescribed, the back surface metallization of the solar cell would lacksilver contact pads 3320 (FIG. 31A) or 3325 (FIG. 31B), but anedge-connected or bus-like aluminum interconnect could be bonded toaluminum (or tin) contact 3310 at locations corresponding to thosecontact pads.

Differential thermal expansion between hidden tap interconnects (orinterconnects to front or rear surface super cell terminal contacts) andsilicon solar cells, and the resulting stress on the solar cell and theinterconnect, can lead to cracking and other failure modes that candegrade performance of the solar module. Consequently, it is desirablethat the hidden tap and other interconnects be configured to accommodatesuch differential expansion without significant stress developing. Theinterconnects may provide stress and thermal expansion relief by, forexample, being formed from highly ductile materials (e.g., soft copper,very thin copper sheet), being formed from low thermal expansioncoefficient materials (e.g., Kovar, Invar or other low thermal expansioniron-nickel alloys) or from materials having a thermal expansioncoefficient approximately matching that of silicon, incorporatingin-plane geometric expansion features such as slits, slots, holes, ortruss structures that accommodate differential thermal expansion betweenthe interconnect and the silicon solar cell, and/or employingout-of-plane geometric features such as kinks, jogs, or dimples thataccommodate such differential thermal expansion. Portions of theinterconnects bonded to hidden tap contact pads (or bonded to super cellfront or rear surface terminal contact pads as described below) may havea thickness of, for example, less than about 100 microns, less thanabout 50 microns, less than about 30 microns, or less than about 25microns to increase the flexibility of the interconnects.

Referring again to FIGS. 7A, 7B-1, and 7B-2, these figures show severalexample interconnect configurations, designated by reference numerals400A-400U, that employ stress-relieving geometrical features and may besuitable for use as interconnects for hidden taps or for electricalconnections to front or rear surface super cell terminal contacts. Theseinterconnects typically have a length approximately equal to the lengthof the long sides of a rectangular solar cell to which they are bonded,but they may have any other suitable length. Example interconnects400A-400T shown in FIG. 7A employ various in-plane stress-relievingfeatures. Example interconnect 400U shown in the in-plane (x-y) view ofFIG. 7B-1 and in the out-of-plane (x-z) view of FIG. 7B-2 employs bends3705 as out of-plane-stress relieving features in a thin metal ribbon.Bends 3705 reduce the apparent tensile stiffness of the metal ribbon.The bends allow the ribbon material to locally bend instead of onlyelongating when the ribbon is under tension. For thin ribbons, this cansignificantly reduce the apparent tensile stiffness by, for example, 90%or more. The exact amount of apparent tensile stiffness reductiondepends on several factors, including the number of bends, geometry ofthe bends, and the thickness of the ribbon. An interconnect may alsoemploy in-plane and out-of-plane stress-relieving features incombination.

FIGS. 37A-1 to 38B-2, further discussed below, show several exampleinterconnect configurations that employ in-plane and/or out-of-planestress relieving geometrical features and may be suitable for use asedge-connected interconnects for hidden taps.

To reduce or minimize the number of conductor runs needed to connecteach hidden tap, a hidden tap interconnect bus may be utilized. Thisapproach connects adjacent super cell hidden tap contact pads to oneanother by using a hidden tap interconnect. (The electrical connectionis typically positive-to-positive or negative-to-negative, i.e. the samepolarity at each end).

For example, FIG. 32 shows a first hidden tap interconnect 3400 runningsubstantially the full width of a solar cell 10 in a first super cell100 and conductively bonded to hidden tap contact pads 3325 arranged asshown in FIG. 31B, and a second hidden tap interconnect 3400 running thefull width of a corresponding solar cell in a super cell 100 in anadjacent row and similarly conductively bonded to hidden tap contactpads 3325 arranged as shown in FIG. 31B. The two interconnects 3400 arearranged in line with and optionally abutting or overlapping each other,and may be conductively bonded to each other or otherwise electricallyconnected to form a bus interconnecting the two adjacent super cells.This scheme may be extended across additional rows (e.g., all rows) ofsuper cells as desired to form a parallel segment of a solar modulecomprising segments of several adjacent super cells. FIG. 33 shows aperspective view of a portion of a super cell from FIG. 32.

FIG. 35 shows an example in which super cells in adjacent rows areinterconnected by a short interconnect 3400 that spans the gap betweenthe super cells and is conductively bonded to a hidden tap contact pad3320 on one super cell and to another hidden tap contact pad 3320 on theother super cell, with the contact pads arranged as shown in FIG. 32A.FIG. 36 shows a similar arrangement in which a short interconnect spansthe gap between two super cells in adjacent rows and is conductivelybonded to the end of a central copper bus portion of the back surfacemetallization on one super cell and to an adjacent end of a centralcopper bus portion of the back surface metallization of the other supercell, with the copper back surface metallization configured as shown inFIG. 31C. In both examples the interconnection schemes may be extendedacross additional rows (e.g., all rows) of super cells as desired toform a parallel segment of a solar module comprising segments of severaladjacent super cells.

FIGS. 37A-1 to 37F-3 show in plane (x-y) and out-of-plane (x-z) views ofexample short hidden tap interconnects 3400 comprising in-plane stressrelieving features 3405. (The x-y plane is the plane of the solar cellback surface metallization pattern). In the examples of FIGS. 37A-1 to37E-2 each interconnect 3400 comprises tabs 3400A and 3400B positionedon opposite sides of one or more in-plane stress-relieving features.Example in-plane stress relieving features include arrangements of one,two, or more hollow diamond shapes, zig-zags, and arrangements of one,two, or more slots.

The term “in plane stress relieving feature” as used herein can alsorefer to the thickness or ductility of the interconnect or of a portionof the interconnect. For example, interconnect 3400 shown in FIGS. 37F-1to 37F-3 is formed from a straight flat length of thin copper ribbon orcopper foil having a thickness T in the x-y plane of, for example, lessthan or equal to about 100 microns, less than or equal to about 50microns, less than or equal to about 30 microns, or less than or equalto about 25 microns to increase the flexibility of the interconnect. Thethickness T may be, for example, about 50 microns. The length L of theinterconnect may be, for example, about 8 centimeters (cm) and the widthW of the interconnect may be, for example, about 0.5 cm. FIGS. 37F-3 and37F-1 show, respectively, front and rear surface views of theinterconnect in the x-y plane. The front surface of the interconnectfaces the rear surface of the solar module. Because the interconnect mayspan the gap between two parallel rows of super cells in a solar module,a portion of the interconnect may be visible through that gap from thefront of the solar module. Optionally, that visible portion of theinterconnect may be blackened, e.g. coated with a black polymer layer,to reduce its visibility. In the illustrated example, a central portion3400C of the front surface of the interconnect having a length L2 ofabout 0.5 cm is coated with a thin black polymer layer. Typically, L2 isgreater than or equal to the width of the gap between super cell rows.The black polymer layer may have a thickness of, for example, about 20microns. Such a thin copper ribbon interconnect may optionally alsoemploy in-plane or out-of-plane stress relieving features as describedabove. For example, the interconnect may include stress-relievingout-of-plane bends as described above with respect to FIGS. 7B-1 and7B-2.

FIGS. 38A-1 to 38B-2 show in plane (x-y) and out-of-plane (x-z) views ofexample short hidden tap interconnects 3400 comprising out-of-planestress relieving features 3407. In the examples each interconnect 3400comprises tabs 3400A and 3400B positioned on opposite sides of one ormore out-of-plane stress-relieving features. Example out-of-plane stressrelieving features include arrangements of one, two, or more bends,kinks, dimples, jogs, or ridges.

The types and arrangements of stress relieving features illustrated inFIGS. 37A-1 to 37E-2 and 38A-1 to 38B-2, and the interconnect ribbonthicknesses described above with respect to FIGS. 37F-1 to 37F-3, mayalso be employed in long hidden tap interconnects as described above andin interconnects bonded to super cell rear or front surface terminalcontacts, as suitable. An interconnect may comprise both in-plane andout-of plane stress relieving features in combination. The in-plane andout-of-plane stress relieving features are designed to reduce orminimize strain and stress effects on the solar cell joint and therebycreate highly reliable and resilient electrical connections.

FIGS. 39A-1 and 39A-2 show example configurations for short hidden tapinterconnects comprising cell contact pad alignment and super cell edgealignment features to facilitate automation, ease of manufacturing andplacement accuracy. FIGS. 39B-1 and 39B-2 show an example configurationfor short hidden tap interconnects that comprise asymmetric tab lengths.Such asymmetric interconnects may be used in opposite orientations toavoid overlap of conductors running parallel to the long axis of thesuper cells. (See discussion of FIGS. 42A-42B below).

Hidden taps as described herein may form the electrical connectionsneeded in module layout to provide a desired module electrical circuit.Hidden tap connections may be made, for example, at intervals of 12, 24,36, or 48 solar cells along a super cell, or at any other suitableinterval. The interval between hidden taps may be determined based onthe application.

Each super cell typically comprises a front surface terminal contact atone end of the super cell and a rear surface terminal contact at theother end of the super cell. In variations in which a super cell spansthe length or width of the solar module, these terminal contacts arelocated adjacent to opposite edges of the solar module.

A flexible interconnect may be conductively bonded to a front or rearsurface terminal contact of a super cell to electrically connect thesuper cell to other solar cells or to other electrical components in themodule. For example, FIG. 34A shows a cross-sectional view of an examplesolar module with an interconnect 3410 conductively bonded to a rearsurface terminal contact at the end of a super cell. Rear surfaceterminal contact interconnect 3410 may be or comprise, for example, athin copper ribbon or foil having a thickness perpendicular to thesurface of the solar cell to which it is bonded of less than or equal toabout 100 microns, less than or equal to about 50 microns, less than orequal to about 30 microns, or less than or equal to about 25 microns toincrease the flexibility of the interconnect. The interconnect may havea width of, for example, greater than or equal to about 10 mm in theplane of the surface of the solar cell in a direction perpendicular tothe flow of current though the interconnect to improve conduction. Asillustrated, a rear surface terminal contact interconnect 3410 may liebehind the solar cells, with no portion of the interconnect extendingbeyond the super cell in the direction parallel to the super cell row.

Similar interconnects may be used to connect to front surface terminalcontacts. Alternatively, to reduce the area of the front surface of thesolar module occupied by front surface terminal interconnects, a frontsurface interconnect may comprise a thin flexible portion directlybonded to the super cell and a thicker portion providing a higherconductivity. This arrangement reduces the width of the interconnectnecessary to achieve a desired conductivity. The thicker portion of theinterconnect may be an integral portion of the interconnect, forexample, or may be a separate piece bonded to the thinner portion of theinterconnect. For example, FIGS. 34B-34C each show a cross-sectionalview of an example interconnect 3410 conductively bonded to a frontsurface terminal contact at an end of a super cell. In both examples athin flexible portion 3410A of the interconnect directly bonded to thesuper cell comprises a thin copper ribbon or foil having a thicknessperpendicular to the surface of the solar cell to which it is bonded ofless than or equal to about 100 microns, less than or equal to about 50microns, less than or equal to about 30 microns, or less than or equalto about 25. A thicker copper ribbon portion 3410B of the interconnectis bonded to thin portion 3410A to improve the conductivity of theinterconnect. In FIG. 34B, an electrically conductive tape 3410C on therear surface of thin interconnect portion 3410A bonds the thininterconnect portion to the super cell and to thick interconnect portion3410B. In FIG. 34C, thin interconnect portion 3410A is bonded to thickinterconnect portion 3410B with an electrically conductive adhesive3410D and bonded to the super cell with an electrically conductiveadhesive 3410E. Electrically conductive adhesives 3410D and 3410E may bethe same or different. Electrically conductive adhesive 3410E may be,for example, a solder.

Solar modules described in this specification may comprise a laminatestructure as shown in FIG. 34A, with super cells and one or moreencapsulant materials 3610 sandwiched between a transparent front sheet3620 and a back sheet 3630. The transparent front sheet may be glass,for example. The back sheet may also be glass, or any other suitablematerial. An extra strip of encapsulant may be disposed between a rearsurface terminal interconnect 3410 and the rear surface of the supercell, as illustrated.

As noted above, hidden taps afford an “all black” module aesthetic.Because these connections are made with conductors that are typicallyhighly reflective, they would normally be of high contrast to theattached solar cells. However, by forming the connections on the backsurface of the solar cells and by also routing other conductors in thesolar module circuit behind the solar cells the various conductors arehidden from view. This allows multiple connection points (hidden taps)while still maintaining the “all black” appearance.

Hidden taps can be used to form various module layouts. In the exampleof FIG. 40 (physical layout) and FIG. 41 (electrical schematic), a solarmodule comprises six super cells each of which run the length of themodule. Hidden tap contact pads and short interconnects 3400 segmenteach super cell into thirds and electrically connect adjacent super cellsegments in parallel, thereby forming three groups of parallel connectedsuper cell segments. Each group is connected in parallel with adifferent one of bypass diodes 1300A-1300C incorporated into (embeddedin) the module's laminate construction. The bypass diodes may belocated, for example, directly behind super cells or between supercells. The bypass diodes may be located approximately along a centerline of the solar module parallel to the long sides of the solar module,for example.

In the example of FIGS. 42A-42B (also corresponding to the electricalschematic of FIG. 41), a solar module comprises six super cells each ofwhich run the length of the module. Hidden tap contact pads and shortinterconnects 3400 segment each super cell into thirds and electricallyconnect adjacent super cell segments in parallel, thereby forming threegroups of parallel connected super cell segments. Each group isconnected in parallel with a different one of bypass diodes 1300A-1300Cthrough bus connections 1500A-1500C, which are located behind the supercells and connect the hidden tap contact pads and short interconnects tothe bypass diodes located in the back of the module within a junctionbox.

FIG. 42B provides a detailed view of the connection of short hidden tapinterconnects 3400 and conductors 1500B and 1500C. As depicted theseconductors do not overlap each other. In the illustrated example this isenabled by the use of asymmetric interconnects 3400 arranged in oppositeorientations. An alternative approach to avoiding overlap of theconductors is to employ a first symmetric interconnect 3400 having tabsof one length and a second symmetric interconnect 3400 having tabs of adifferent length.

In the example of FIG. 43 (also corresponding to the electricalschematic of FIG. 41), a solar module is configured similarly to asshown in FIG. 42A except that hidden tap interconnects 3400 formcontinuous buses that run substantially the full width of the solarmodule. Each bus may be a single long interconnect 3400 conductivelybonded to the back surface metallization of each super cell.Alternatively, the bus may comprise multiple individual interconnects,each spanning a single super cell, conductively bonded to each other orotherwise electrically interconnected as described above with respect toFIG. 41. FIG. 43 also shows super cell terminal interconnects 3410forming a continuous bus along one end of the solar module toelectrically connect the front surface terminal contacts of the supercells, and additional super cell terminal interconnects 3410 forming acontinuous bus along the opposite end of the solar module toelectrically connect the rear surface terminal contacts of the supercells.

The example solar module of FIGS. 44A-44B also corresponds to theelectrical schematic of FIG. 41. This example employs short hidden tapinterconnects 3400 as in FIG. 42A and interconnects 3410 formingcontinuous buses for the super cell front and rear surface terminalcontacts, as in FIG. 43.

In the example of FIG. 47A (physical layout) and FIG. 47B (electricalschematic), a solar module comprises six super cells each of which runthe full length of the solar module. Hidden tap contact pads and shortinterconnects 3400 segment each super cell into a ⅔ length section and a⅓ length section. Interconnects 3410 at the lower edge of the solarmodule (as depicted in the drawing) interconnect the left hand threerows in parallel with each other, the right hand three rows in parallelwith each other, and the left hand three rows in series with the righthand three rows. This arrangement forms three groups of parallelconnected super cell segments with each super cell group having a lengthof ⅔ the length of a super cell. Each group is connected in parallelwith a different one of bypass diodes 2000A-2000C. This arrangementprovides about twice the voltage and about half of the current thatwould be provided by the same super cells if they were insteadelectrically connected as shown in FIG. 41.

As noted above with reference to FIG. 34A, interconnects bonded to supercell rear surface terminal contacts may lie entirely behind the supercells and be hidden from view from the front (sun) side of the solarmodule. Interconnects 3410 bonded to super cell front surface terminalcontacts may be visible in a rear view of the solar module (e.g., as inFIG. 43) because they extend beyond the ends of the super cells (e.g.,as in FIG. 44A) or because they fold around and under the ends of thesuper cells.

The use of hidden taps facilitates grouping small numbers of solar cellsper bypass diode. In the examples of FIGS. 48A-48B (each showing aphysical layout), a solar module comprises six super cells each of whichrun the length of the module. Hidden tap contact pads and shortinterconnects 3400 segment each super cell into fifths and electricallyconnect adjacent super cell segments in parallel, thereby forming fivegroups of parallel connected super cell segments. Each group isconnected in parallel with a different one of bypass diodes 2100A-2100Eincorporated into (embedded in) the module's laminate construction. Thebypass diodes may be located, for example, directly behind super cellsor between super cells. Super cell terminal interconnects 3410 form acontinuous bus along one end of the solar module to electrically connectthe front surface terminal contacts of the super cells, and additionalsuper cell terminal interconnects 3410 form a continuous bus along theopposite end of the solar module to electrically connect the rearsurface terminal contacts of the super cells. In the example of FIG.48A, a single junction box 2110 is electrically connected to the frontand rear surface terminal interconnect buses by conductors 2115A and2115B. There are no diodes in the junction box, however, soalternatively (FIG. 48B) the long return conductors 2215A and 2115B canbe eliminated and the single junction box 2110 replaced with two singlepolarity (+ or −) junction boxes 2110A-2110B located, for example, atopposite edges of the module. This eliminates resistive loss in the longreturn conductors.

Although the examples described herein use hidden taps to electricallysegment each super cell into three or five groups of solar cells, theseexamples are intended to be illustrative but not limiting. Moregenerally, hidden taps may be used to electrically segment a super cellinto more or fewer groups of solar cells then illustrated, and/or intomore or fewer solar cells per group then illustrated.

In normal operation of the solar modules described herein, with nobypass diode forward biased and in conduction, little or no currentflows through any hidden tap contact pad. Instead, current flows throughthe length of each super cell through the cell-to-cell conductive bondsformed between adjacent overlapping solar cells. In contrast, FIG. 45shows current flow when a portion of the solar module is bypassedthrough a forward biased bypass diode. As indicated by the arrows, inthis example current in the leftmost super cell flows along the supercell until it reaches the tapped solar cell, then through that solarcell's back surface metallization, a hidden tap contact pad (not shown),an interconnect 3400 to a second solar cell in the adjacent super cell,another hidden tap contact pad (not shown) to which the interconnect isbonded on the second solar cell, through the back surface metallizationof the second solar cell, and through additional hidden tap contactpads, interconnects, and solar cell back surface metallization to reachbus connection 1500 to the bypass diode. Current flow through the othersuper cells is similar. As is apparent from the illustration, under suchcircumstances hidden tap contact pads may conduct current from two ormore rows of super cells, and thus conduct a current greater than thecurrent generated in any single solar cell in the module.

Typically there is no bus bar, contact pad, or other light blockingelement (other than front surface metallization fingers or anoverlapping portion of an adjacent solar cell) on the front surface of asolar cell opposite from a hidden tap contact pad. Consequently, if thehidden tap contact pad is formed from silver on a silicon solar cell,the light conversion efficiency of the solar cell in the region of thehidden tap contact pad may be reduced if the silver contact pad reducesthe effect of a back surface field that prevents back surface carrierrecombination. In order to avoid this loss of efficiency, typically mostof the solar cells in a super cell do not comprise hidden tap contactpads. (For example, in some variations only those solar cells for whicha hidden tap contact pad is necessary for a bypass diode circuit willcomprise such a hidden tap contact pad). Further, to match the currentgeneration in solar cells that include hidden tap contact pads to thecurrent generation in solar cells that lack hidden tap contact pads, thesolar cells comprising hidden tap contact pads may have a larger lightcollection area than the solar cells lacking hidden tap contact pads.

Individual hidden tap contact pads may have rectangular dimensions of,for example, less than or equal to about 2 mm by less than or equal toabout 5 mm.

Solar modules are subject to temperature cycling as a result oftemperature variations in their installed environment, during operation,and during testing. As shown in FIG. 46A, during such temperaturecycling a mismatch in thermal expansion between the silicon solar cellsin the super cell and other portions of the module, for example a glassfront sheet of the module, results in relative motion between the supercell and the other portions of the module along the long axis of thesuper cell rows. This mismatch tends to stretch or compress the supercells, and may damage the solar cells or the conductive bonds betweensolar cells in the super cells. Similarly, as shown in FIG. 46B, duringtemperature cycling a mismatch in thermal expansion between aninterconnect bonded to a solar cell and the solar cell results inrelative motion between the interconnect and the solar cell in thedirection perpendicular to the rows of super cells. This mismatchstrains and may damage the solar cells, the interconnect, and theconductive bond between them. This may occur for interconnects bonded tohidden tap contact pads and for interconnects bonded to super cell frontor rear surface terminal contacts.

Similarly, cyclical mechanical loading of a solar module, for exampleduring shipping or from weather (e.g. wind and snow), can create localshear forces at the cell-to-cell bonds within a super cell and at thebond between a solar cell and an interconnect. These shear forces canalso damage the solar module.

To prevent problems arising from relative motion between the super cellsand other portions of the solar module along the long axis of the supercell rows, the conductive adhesive used to bond adjacent overlappingsolar cells to each other may be selected to form a flexible conductivebond 3515 (FIG. 46A) between overlapping solar cells that providesmechanical compliance to the super cells accommodating a mismatch inthermal expansion between the super cells and a glass front sheet of themodule in a direction parallel to the rows for a temperature range ofabout −40° C. to about 100° C. without damaging the solar module. Theconductive adhesive may be selected to form conductive bonds having ashear modulus at standard test conditions (i.e., 25° C.) of, forexample, less than or equal to about 100 megapascals (MPa), less than orequal to about 200 MPa, less than or equal to about 300 MPa, less thanor equal to about 400 MPa, less than or equal to about 500 MPa, lessthan or equal to about 600 MPa, less than or equal to about 700 MPa,less than or equal to about 800 MPa, less than or equal to about 900MPa, or less than or equal to about 1000 MPa. The flexible conductivebonds between overlapping adjacent solar cells may accommodatedifferential motion between each cell and the glass front sheet ofgreater than or equal to about 15 microns, for example. Suitableconductive adhesives may include, for example, ECM 1541-S3 availablefrom Engineered Conductive Materials LLC.

To promote the flow of heat along a super cell, which reduces the riskof damage to the solar module from hot spots that may arise duringoperation of the solar module if a solar cell in the module is reversebiased as a resulting of shading or for some other reason, conductivebonds between overlapping adjacent solar cells may be formed with, forexample, a thickness perpendicular to the solar cells of less than orequal to about 50 microns and a thermal conductivity perpendicular tothe solar cells greater than or equal to about 1.5 W/(meter-K).

To prevent problems arising from relative motion between an interconnectand a solar cell to which it is bonded, the conductive adhesive used tobond the interconnect to the solar cell may be selected to form aconductive bond between the solar cell and the interconnect that issufficiently stiff to force the interconnect to accommodate a mismatchin thermal expansion between the solar cell and the interconnect for atemperature range of about −40° C. to about 180° C. without damaging thesolar module. This conductive adhesive may be selected to form aconductive bond having a shear modulus at standard test conditions(i.e., 25° C.) of, for example, greater than or equal to about 1800 MPa,greater than or equal to about 1900 MPa, greater than or equal to about2000 MPa, greater than or equal to about 2100 MPa, greater than or equalto about 2200 MPa, greater than or equal to about 2300 MPa, greater thanor equal to about 2400 MPa, greater than or equal to about 2500 MPa,greater than or equal to about 2600 MPa, greater than or equal to about2700 MPa, greater than or equal to about 2800 MPa, greater than or equalto about 2900 MPa, greater than or equal to about 3000 MPa, greater thanor equal to about 3100 MPa greater than or equal to about 3200 MPa,greater than or equal to about 3300 MPa, greater than or equal to about3400 MPa, greater than or equal to about 3500 MPa, greater than or equalto about 3600 MPa, greater than or equal to about 3700 MPa, greater thanor equal to about 3800 MPa, greater than or equal to about 3900 MPa, orgreater than or equal to about 4000 MPa. In such variations theinterconnect may withstand thermal expansion or contraction of theinterconnect of greater than or equal to about 40 microns, for example.Suitable conductive adhesives may include, for example, Hitachi CP-450and solders.

Hence, the conductive bonds between overlapping adjacent solar cellswithin a super cell may utilize a different conductive adhesive than theconductive bonds between the super cell and the flexible electricalinterconnect. For example, the conductive bond between the super celland the flexible electrical interconnect may be formed from a solder,and the conductive bonds between overlapping adjacent solar cells formedfrom a non-solder conductive adhesive. In some variations, bothconductive adhesives can be cured in a single process step, for examplein an about 150° C. to about 180° C. process window.

The above discussion has focused upon assembling a plurality of solarcells (which may be cut solar cells) in a shingled manner on a commonsubstrate. This results in the formation of a module.

In order to gather a sufficient amount of solar energy to be useful,however, an installation typically comprises a number of such modulesthat are themselves assembled together. According to embodiments, aplurality of solar cell modules may also be assembled in a shingledmanner to increase the area efficiency of an array.

In particular embodiments, a module may feature a top conductive ribbonfacing a direction of solar energy, and a bottom conductive ribbonfacing away from the direction of solar energy.

The bottom ribbon is buried beneath the cells. Thus, it does not blockincoming light and adversely impact an area efficiency of the module. Bycontrast, the top ribbon is exposed and can block the incoming light andadversely impact efficiency.

According to embodiments the modules themselves can be shingled, suchthat the top ribbon is covered by the neighboring module. This shingledmodule configuration could also provide for additional area on themodule for other elements, without adversely impacting a final exposedarea of the module array. Examples of module elements that may bepositioned in overlapping regions can include but are not limited to,junction boxes (j-boxes) and/or bus ribbons.

In certain embodiments, j-boxes of the respective adjacent shingledmodules and are in a mating arrangement in order to achieve electricalconnection between them. This simplifies the configuration of the arrayof shingled modules by eliminating wiring.

In certain embodiments, the j-boxes could be reinforced and/or combinedwith additional structural standoffs. Such a configuration could createan integrated tilted module roof mount rack solution, wherein adimension of the junction box determines a tilt. Such an implementationmay be particularly useful where an array of shingled modules is mountedon a flat roof.

Shingled super cells open up unique opportunities for module layout withrespect to module level power management devices (for example, DC/ACmicro-inverters, DC/DC module power optimizers, voltage intelligence andsmart switches, and related devices). A feature of module level powermanagement systems is power optimization. Super cells as described andemployed herein may produce higher voltages than traditional panels. Inaddition, super cell module layout may further partition the module.Both higher voltages and increased partitioning create potentialadvantages for power optimization.

This specification discloses high-efficiency solar modules (i.e., solarpanels) comprising narrow rectangular silicon solar cells arranged in ashingled manner and electrically connected in series to form supercells, with the super cells arranged in physically parallel rows in thesolar module. The super cells may have lengths spanning essentially thefull length or width of the solar module, for example, or two or moresuper cells may be arranged end-to-end in a row. Each super cell mayinclude any number of solar cells, including in some variations at leastnineteen solar cells and in certain variations greater than or equal to100 silicon solar cells, for example. Each solar module may have aconventional size and shape and yet include hundreds of silicon solarcells, allowing the super cells in a single solar module to beelectrically interconnected to provide a direct current (DC) voltage offor example, about 90 Volts (V) to about 450 V or more.

As further described below, this high DC voltage facilitates conversionfrom direct to alternating current (AC) by an inverter (e.g.,microinverter located on the solar module) by eliminating or reducingthe need for a DC to DC boost (step-up in DC voltage) prior toconversion to AC by the inverter. Also as further described below, thehigh DC voltage also facilitates the use of arrangements in which DC/ACconversion is performed by a central inverter receiving high voltage DCoutput from two or more high voltage shingled solar cell moduleselectrically connected in parallel with each other.

Turning now to the figures for a more detailed understanding of thesolar modules described in this specification, FIG. 1 shows across-sectional view of a string of series-connected solar cells 10arranged in a shingled manner with the ends of adjacent solar cellsoverlapping and electrically connected to form a super cell 100. Eachsolar cell 10 comprises a semiconductor diode structure and electricalcontacts to the semiconductor diode structure by which electric currentgenerated in solar cell 10 when it is illuminated by light may beprovided to an external load.

In the examples described in this specification, each solar cell 10 is arectangular crystalline silicon solar cell having front (sun side)surface and rear (shaded side) surface metallization patterns providingelectrical contact to opposite sides of an n-p junction, the frontsurface metallization pattern is disposed on a semiconductor layer ofn-type conductivity, and the rear surface metallization pattern isdisposed on a semiconductor layer of p-type conductivity. However, othermaterial systems, diode structures, physical dimensions, or electricalcontact arrangements may be used if suitable. For example, the front(sun side) surface metallization pattern may be disposed on asemiconductor layer of p-type conductivity, and the rear (shaded side)surface metallization pattern disposed on a semiconductor layer ofn-type conductivity.

Referring again to FIG. 1, in super cell 100 adjacent solar cells 10 areconductively bonded to each other in the region in which they overlap byan electrically conducting bonding material that electrically connectsthe front surface metallization pattern of one solar cell to the rearsurface metallization pattern of the adjacent solar cell. Suitableelectrically conducting bonding materials may include, for example,electrically conducting adhesives and electrically conducting adhesivefilms and adhesive tapes, and conventional solders.

FIG. 2 shows an example rectangular solar module 200 comprising sixrectangular super cells 100, each of which has a length approximatelyequal to the length of the long sides of the solar module. The supercells are arranged as six parallel rows with their long sides orientedparallel to the long sides of the module. A similarly configured solarmodule may include more or fewer rows of such side-length super cellsthan shown in this example. In other variations the super cells may eachhave a length approximately equal to the length of a short side of arectangular solar module, and be arranged in parallel rows with theirlong sides oriented parallel to the short sides of the module. In yetother arrangements each row may comprise two or more super cellselectrically interconnected in series. The modules may have shorts sideshaving a length, for example, of about 1 meter and long sides having alength, for example, of about 1.5 to about 2.0 meters. Any othersuitable shapes (e.g., square) and dimensions for the solar modules mayalso be used.

In some variations, the conductive bonds between overlapping solar cellsprovide mechanical compliance to the super cells accommodating amismatch in thermal expansion between the super cells and a glass frontsheet of the solar module in a direction parallel to the rows for atemperature range of about −40° C. to about 100° C. without damaging thesolar module.

Each super cell in the illustrated example comprises 72 rectangularsolar cells each having a width equal or approximately equal to ⅙ thewidth of a conventionally sized 156 mm square or pseudo square siliconwafer and a length equal or approximately equal to the width of thesquare or pseudo square waver. More, generally, rectangular siliconsolar cells employed in the solar modules described herein may havelengths, for example, equal to or approximately equal to the width of aconventionally sized square or pseudo square silicon wafer and widths,for example, equal to or approximately equal to 1/M the width of aconventionally sized square or pseudo square waver, with M anyinteger≦20. M may be for example 3, 4, 5, 6 or 12. M may also be greaterthan 20. A super cell may comprise any suitable number of suchrectangular solar cells.

The super cells in solar module 200 may be interconnected in series byelectrical interconnects (optionally, flexible electrical interconnects)or by module level power electronics as described below to provide froma conventionally sized solar module a higher than conventional voltage,because the shingling approach just described incorporates many morecells per module than is conventional. For example, a conventionallysized solar module comprising super cells made from ⅛th cut siliconsolar cells may comprise over 600 solar cells per module. In comparison,a conventionally sized solar module comprising conventionally sized andinterconnected silicon solar cells typically comprises about 60 solarcells per module. In conventional silicon solar modules, square orpseudo square solar cells are typically interconnected by copper ribbonsand spaced apart from each other to accommodate the interconnections. Insuch cases, cutting the conventionally sized square or pseudo squarewafers into narrow rectangles would reduce the total amount of activesolar cell area in the module and therefore reduce module power becauseof the additional cell-to-cell interconnects required. In contrast, inthe solar modules disclosed herein the shingled arrangement hidescell-to-cell electrical interconnections beneath active solar cell area.Consequently the solar modules described herein may provide high outputvoltages without reducing module output power because there is little orno tradeoff between module power and the number of solar cells (andrequired cell-to-cell interconnections) in the solar module.

When all the solar cells are connected in series, a shingled solar cellmodule as described herein may provide a DC voltage in the range ofabout 90 volts to about 450 Volts or more, for example. As noted above,this high DC voltage may be advantageous.

For example, a microinverter disposed on or near a solar module may beused for module level power optimization and DC to AC conversion.Referring now to FIGS. 49A-49B, conventionally a microinverter 4310receives a 25 V to 40 V DC input from a single solar module 4300 andoutputs a 230 V AC output to match the connected grid. The microinvertertypically comprises two major components, a DC/DC boost and DC/ACinversion. The DC/DC boost is utilized to increase the DC bus voltageneeded for the DC/AC conversion, and is typically the most expensive andlossy (2% efficiency loss) component. Because the solar modulesdescribed herein provide a high voltage output, the need for a DC/DCboost may be reduced or eliminated (FIG. 49B). This may reduce cost andincrease efficiency and reliability of the solar module 200.

In conventional arrangements using a central (“string”) inverter ratherthan microinverters, conventional low DC output solar modules areelectrically connected in series with each other and to the stringinverter. The voltage produced by the string of solar modules is equalto the sum of the individual module voltages, because the modules areconnected in series. A permissible voltage range determines the maximumand minimum number of modules in the string. The maximum number ofmodules is a set by the module voltage and the code voltage limits: forexample N_(max)×V_(oc)<600 V (US residential standard) orN_(max)×V_(oc)<1,000 V (commercial standard). The minimum number ofmodules in the series is set by the module voltage and the minimumoperating voltage required by the string inverter:N_(max)×V_(mp)>V_(Invertermin). The minimum operating voltage(V_(Invertermin)) required by the string inverter (e.g., a Fronius,Powerone, or SMA inverter) is typically between about 180 V and about250 V. Typically, the optimal operating voltage for the string inverteris about 400 V.

A single high DC voltage shingled solar cell module as described hereinmay produce a voltage greater than the minimum operating voltagerequired by a string inverter, and optionally at or near the optimumoperating voltage for the string inverter. As a consequence, the high DCvoltage shingled solar cell modules described herein may be electricallyconnected in parallel with each other to a string inverter. This avoidsthe string length requirements of series connected module strings, whichcan complicate system design and installation. Also, in a seriesconnected string of solar modules the lowest current module dominates,and the system cannot operate efficiently if different modules in thestring receive different illumination as may occur for modules ondifferent roof slopes or as a result of tree shade. The parallel highvoltage module configurations described herein may avoid these problemsas well, because the current through each solar module is independentfrom the current through the other solar modules. Further, sucharrangements need not require module level power electronics and thusmay improve reliability of the solar modules, which may be particularlyimportant in variations in which the solar modules are deployed on aroof top.

Referring now to FIGS. 50A-50B, as described above, a super cell may runapproximately the full length or width of the solar module. To enableelectrical connections along the length of the super cell, a hidden(from front view) electrical tapping point may be integrated into thesolar module construction. This may be accomplished by connecting anelectrical conductor to the back surface metallization of a solar cellat an end or intermediate location in the super cell. Such hidden tapsallow electrical segmentation of a super cell, and enableinterconnection of super cells or segments of super cells to bypassdiodes, module level power electronics (e.g. a microinverter, poweroptimizers, voltage intelligence and smart switches, and relateddevices), or other components. The use of hidden taps is furtherdescribed in U.S. Provisional Application No. 62/081,200, U.S.Provisional Application No. 62/133,205, and U.S. application Ser. No.14/674,983, each of which is incorporated herein by reference in itsentirety.

In the examples of FIG. 50A (an example physical layout) and FIG. 50B(an example electrical schematic), the illustrated solar modules 200each comprise six super cells 100 electrically connected in series toprovide a high DC voltage. Each super cell is electrically segmentedinto several groups of solar cells by hidden taps 4400, with each groupof solar cells electrically connected in parallel with a differentbypass diode 4410. In these examples the bypass diodes are disposedwithin the solar module laminate structure, i.e., with the solar cellsin an encapsulant between a front surface transparent sheet and abacking sheet. Alternatively, the bypass diodes may be disposed in ajunction box located on a rear surface or edge of the solar module, andinterconnected to the hidden taps by conductor runs.

In the examples of FIG. 51A (physical layout) and FIG. 51B(corresponding electrical schematic), the illustrated solar module 200also comprises six super cells 100 electrically connected in series toprovide a high DC voltage. In this example, the solar module iselectrically segmented into three pairs of series connected super cells,with each pair of super cells electrically connected in parallel with adifferent bypass diode. In this example the bypass diodes are disposedwithin a junction box 4500 located on a back surface of the solarmodule. The bypass diodes could instead be located in the solar modulelaminate structure or in an edge-mounted junction box.

In the examples of FIGS. 50A-51B, in normal operation of the solarmodule each solar cell is forward biased and all bypass diodes aretherefore reverse biased and not conducting. If one or more solar cellsin a group is reverse biased to a sufficiently high voltage, however,the bypass diode corresponding to that group will turn on and currentflow through the module will bypass the reverse-biased solar cells. Thisprevents the formation of dangerous hot spots at shaded ormalfunctioning solar cells.

Alternatively, the bypass diode functionality can be accomplished withinmodule level power electronics, e.g. a microinverter, disposed on ornear the solar module. (Module level power electronics and their use mayalso be referred to herein as module level power management devices orsystems and module level power management). Such module level powerelectronics, optionally integrated with the solar module, may optimizethe power from groups of super cells, from each super cell, or from eachindividual super cell segment in electrically segmented super cells(e.g., by operating the group of super cells, super cell, or super cellsegment at its maximum power point), thereby enabling discrete poweroptimization within the module. The module level power electronics mayeliminate the need for any bypass diodes within the module as the powerelectronics may determine when to bypass the entire module, a specificgroup of super cells, one or more specific individual super cells,and/or one or more specific super cell segments.

This may be accomplished, for example, by integrating voltageintelligence at the module level. By monitoring the voltage output of asolar cell circuit (e.g., one or more super cells or super cellsegments) in the solar module, a “smart switch” power management devicecan determine if that circuit includes any solar cells in reverse bias.If a reverse biased solar cell is detected, the power management devicecan disconnect the corresponding circuit from the electrical systemusing, for example, a relay switch or other component. For example, ifthe voltage of a monitored solar cell circuit drops below apredetermined threshold, then the power management device will shut off(open circuit) that circuit. The predetermined threshold may be, forexample a certain percentage or magnitude (e.g. 20% or 10V) compared tonormal operation of the circuit. Implementation of such voltageintelligence may be incorporated into existing module level powerelectronics products (e.g., from Enphase Energy Inc., SolaredgeTechnologies, Inc., Tigo Energy, Inc.) or through a custom circuitdesign.

FIG. 52A (physical layout) and FIG. 52B (corresponding electricalschematic) show an example architecture for module level powermanagement of a high voltage solar module comprising shingled supercells. In this example, rectangular solar module 200 comprises sixrectangular shingled super cells 100 arranged in six rows extending thelength of the long sides of the solar module. The six super cells areelectrically connected in series to provide a high DC voltage. Modulelevel power electronics 4600 may perform voltage sensing, powermanagement, and/or DC/AC conversion for the entire module.

FIG. 53A (physical layout) and FIG. 53B (corresponding electricalschematic) show another example architecture for module level powermanagement of a high voltage solar module comprising shingled supercells. In this example, rectangular solar module 200 comprises sixrectangular shingled super cells 100 arranged in six rows extending thelength of the long sides of the solar module. The six super cells areelectrically grouped into three pairs of series connected super cells.Each pair of super cells is individually connected to module level powerelectronics 4600, which may perform voltage sensing and poweroptimization on the individual pairs of super cells, connect two or moreof them in series to provide a high DC voltage, and/or perform DC/ACconversion.

FIG. 54A (physical layout) and FIG. 54B (corresponding electricalschematic) show another example architecture for module level powermanagement of a high voltage solar module comprising shingled supercells. In this example, rectangular solar module 200 comprises sixrectangular shingled super cells 100 arranged in six rows extending thelength of the long sides of the solar module. Each super cell isindividually connected with module level power electronics 4600, whichmay perform voltage sensing and power optimization on each super cell,connect two or more of them in series to provide a high DC voltage,and/or perform DC/AC conversion.

FIG. 55A (physical layout) and FIG. 55B (corresponding electricalschematic) show another example architecture for module level powermanagement of a high voltage solar module comprising shingled supercells. In this example, rectangular solar module 200 comprises sixrectangular shingled super cells 100 arranged in six rows extending thelength of the long sides of the solar module. Each super cell iselectrically segmented into two or more groups of solar cells by hiddentaps 4400. Each resulting group of solar cells is individually connectedwith module level power electronics 4600, which may perform voltagesensing and power optimization on each solar cell group, connect aplurality of the groups in series to provide a high DC voltage, and/orperform DC/AC conversion.

In some variations two or more high voltage DC shingled solar cellmodules as described herein are electrically connected in series toprovide a high voltage DC output, which is converted to AC by aninverter. The inverter may be a microinverter integrated with one of thesolar modules, for example. In such cases the microinverter mayoptionally be a component of module level power management electronicsthat also perform additional sensing and connecting functions asdescribed above. Alternatively the inverter may be a central “string”inverter as further discussed below.

As shown in FIG. 56, when stringing super cells in series in a solarmodule adjacent rows of super cells may be slightly offset along theirlong axes in a staggered manner. This staggering allows adjacent ends ofsuper cell rows to be electrically connected in series by aninterconnect 4700 bonded to the top of one super cell and to the bottomof the other, while saving module area (space/length) as well asstreamlining manufacturing. Adjacent rows of super cells may be offsetby about 5 millimeters, for example.

Differential thermal expansion between electrical interconnects 4700 andsilicon solar cells and the resulting stress on the solar cell and theinterconnect can lead to cracking and other failure modes that candegrade performance of the solar module. Consequently, it is desirablethat the interconnect be flexible and configured to accommodate suchdifferential expansion without significant stress developing. Theinterconnect may provide stress and thermal expansion relief by, forexample, being formed from highly ductile materials (e.g., soft copper,thin copper sheet), being formed from low thermal expansion coefficientmaterials (e.g., Kovar, Invar or other low thermal expansion iron-nickelalloys) or from materials having a thermal expansion coefficientapproximately matching that of silicon, incorporating in-plane geometricexpansion features such as slits, slots, holes, or truss structures thataccommodate differential thermal expansion between the interconnect andthe silicon solar cell, and/or employing out-of-plane geometric featuressuch as kinks, jogs, or dimples that accommodate such differentialthermal expansion. Conductive portions of the interconnects may have athickness of, for example, less than about 100 microns, less than about50 microns, less than about 30 microns, or less than about 25 microns toincrease the flexibility of the interconnects. (The generally lowcurrent in these solar modules enables use of thin flexible conductiveribbons without excessive power loss resulting from the electricalresistance of the thin interconnects).

In some variations conductive bonds between a super cell and a flexibleelectrical interconnect force the flexible electrical interconnect toaccommodate a mismatch in thermal expansion between the super cell andthe flexible electrical interconnect for a temperature range of about−40° C. to about 180° C. without damaging the solar module.

FIG. 7A (discussed above) shows several example interconnectconfigurations, designated by reference numerals 400A-400T, that employin-plane stress-relieving geometrical features, and FIGS. 7B-1 and 7B-2(also discussed above) show example interconnect configurationsdesignated by reference numerals 400U and 3705 that employ out-of-planestress-relieving geometrical features. Any one of or any combination ofthese interconnect configurations employing stress-relieving featuresmay be suitable for electrically interconnecting super cells in seriesto provide a high DC voltage, as described herein.

The discussion with respect to FIGS. 51A-55B focused on module levelpower management, with possible DC/AC conversion of a high DC modulevoltage by module level power electronics to provide an AC output fromthe module. As noted above, DC/AC conversion of high DC voltages fromshingled solar cell modules as described herein may be performed insteadby a central string inverter. For example, FIG. 57A schematicallyillustrates a photovoltaic system 4800 that comprises a plurality ofhigh DC voltage shingled solar cell modules 200 electrically connectedin parallel with each other to a string inverter 4815 via a high DCvoltage negative bus 4820 and a high DC voltage positive bus 4810.Typically, each solar module 200 comprises a plurality of shingled supercells electrically connected in series with electrical interconnects toprovide a high DC voltage, as described above. Solar modules 200 mayoptionally comprise bypass diodes arranged as described above, forexample. FIG. 57B shows an example deployment of photovoltaic system4800 on a roof top.

In some variations of photovoltaic system 4800, two or more short seriesconnected strings of high DC voltage shingled solar cell modules may beelectrically connected in parallel with a string inverter. Referringagain to FIG. 57A, for example, each solar module 200 may be replacedwith a series connected string of two or more high DC voltage shingledsolar cell modules 200. This might be done, for example, to maximize thevoltage provided to the inverter while complying with regulatorystandards.

Conventional solar modules typically produce about 8 amps Isc (shortcircuit current), about 50 Voc (open circuit voltage), and about 35 Vmp(maximum power point voltage). As discussed above, high DC voltageshingled solar cell modules as described herein comprising M times theconventional number of solar cells, with each of the solar cells havingan area of about 1/M the area of a conventional solar cell, produceroughly M times higher voltage and 1/M the current of a conventionalsolar module. As noted above M can be any suitable integer, is typically≦20, but may be greater than 20. M may be for example 3, 4, 5, 6, or 12.

If M=6, Voc for the high DC voltage shingled solar cell modules may befor example about 300 V. Connecting two such modules in series wouldprovide about 600 V DC to the bus, complying with the maximum set by USresidential standards. If M=4, Voc for the high DC voltage shingledsolar cell modules may be for example about 200 V. Connecting three suchmodules in series would provide about 600 V DC to the bus. If M=12, Vocfor the high DC voltage shingled solar cell modules may be for exampleabout 600 V. One could also configure the system to have bus voltagesless than 600 V. In such variations the high DC voltage shingled solarcell modules may be, for example, connected in pairs or triplets or anyother suitable combination in a combiner box to provide an optimalvoltage to the inverter.

A challenge arising from the parallel configuration of high DC voltageshingled solar cell modules described above is that if one solar modulehas a short circuit the other solar modules could potentially dump theirpower on the shorted module (i.e., drive current through and dissipatepower in the shorted module) and create a hazard. This problem can beaverted, for example, by use of blocking diodes arranged to preventother modules from driving current through a shorted module, use ofcurrent limiting fuses, or use of current limiting fuses in combinationwith blocking diodes. FIG. 57B schematically indicates the use of twocurrent limiting fuses 4830 on the positive and negative terminals of ahigh DC voltage shingled solar cell module 200.

The protective arrangement of blocking diodes and/or fuses may depend onwhether or not the inverter comprises a transformer. Systems using aninverter comprising a transformer typically ground the negativeconductor. Systems using a transformerless inverter typically do notground the negative conductor. For a transformerless inverter, it may bepreferable to have a current limiting fuse in-line with the positiveterminal of the solar module and another current limiting fuse in linewith the negative terminal.

Blocking diodes and/or current limiting fuses may be placed, forexample, with each module in a junction box or in the module laminate.Suitable junction boxes, blocking diodes (e.g., in-line blockingdiodes), and fuses (e.g., in-line fuses) may include those availablefrom Shoals Technology Group.

FIG. 58A shows an example high voltage DC shingled solar cell modulecomprising a junction box 4840 in which a blocking diode 4850 is in linewith the positive terminal of the solar module. The junction box doesnot include a current limiting fuse. This configuration may preferablybe used in combination with one or more current limiting fuses locatedelsewhere (for example in a combiner box) in line with the positiveand/or negative terminals of the solar module (e.g., see FIG. 58Dbelow). FIG. 58B shows an example high voltage DC shingled solar cellmodule comprising a junction box 4840 in which a blocking diode is inline with the positive terminal of the solar module and a currentlimiting fuse 4830 is in line with the negative terminal. FIG. 58C showsan example high voltage DC shingled solar cell module comprising ajunction box 4840 in which a current limiting fuse 4830 is in line withthe positive terminal of the solar module and another current limitingfuse 4830 is in line with the negative terminal. FIG. 58D shows anexample high voltage DC shingled solar cell module comprising a junctionbox 4840 configure as in FIG. 58A, and fuses located outside of thejunction box in line with the positive and negative terminals of thesolar module.

Referring now to FIGS. 59A-59B, as an alternative to the configurationsdescribed above, blocking diodes and/or current limiting fuses for allof the high DC voltage shingled solar cell modules may be placedtogether in a combiner box 4860. In these variations one or moreindividual conductors run separately from each module to the combinerbox. As shown in FIG. 59A, in one option a single conductor of onepolarity (e.g., negative as illustrated) is shared between all modules.In another option (FIG. 59B) both polarities have individual conductorsfor each module. Although FIGS. 59A-59B show only fuses located incombiner box 4860, any suitable combination of fuses and or blockingdiodes may be located in the combiner box. In addition, electronicsperforming other functions such as, for example, monitoring, maximumpower point tracking, and/or disconnecting of individual modules orgroups of modules may be implemented in the combiner box.

Reverse bias operation of a solar module may occur when one or moresolar cells in the solar module are shaded or otherwise generating lowcurrent, and the solar module is operated at a voltage-current pointthat drives a larger current through a low-current solar cell than thelow-current solar cell can handle. A reverse biased solar cell may heatup and create a hazard condition. A parallel arrangement of high DCvoltage shingled solar cell modules, as shown in FIG. 58A for example,may enable the modules to be protected from reverse bias operation bysetting a suitable operating voltage for the inverter. This isillustrated for example by FIGS. 60A-60B.

FIG. 60A shows a plot 4870 of current versus voltage and a plot 4880 ofpower versus voltage for a parallel-connected string of about ten highDC voltage shingled solar modules. These curves were calculated for amodel in which none of the solar modules included a reverse biased solarcell. Because the solar modules are electrically connected in parallel,they all have the same operating voltage and their currents add.Typically, an inverter will vary the load on the circuit to explore thepower-voltage curve, identify the maximum point on that curve, thenoperate the module circuit at that point to maximize output power.

In contrast, FIG. 60B shows a plot 4890 of current versus voltage and aplot 4900 of power versus voltage for the model system of FIG. 60A for acase where some of the solar modules in the circuit include one or morereverse biased solar cells. The reverse-biased modules manifestthemselves in the example current-voltage curve by the formation of aknee shape with a transition from about 10 amp operation at voltagesdown to about 210 volts to about 16 amp operation at voltages belowabout 200 volts. At voltages below about 210 volts the shaded modulesinclude reverse biased solar cells. The reverse-biased modules alsomanifest themselves in the power-voltage curve by the existence of twomaxima: an absolute maximum at about 200 volts and a local maximum atabout 240 volts. The inverter may be configured to recognize such signsof reverse-biased solar modules and operate the solar modules at anabsolute or local maximum power point voltage at which no modules arereverse biased. In the example of FIG. 60B, the inverter may operate themodules at the local maximum power point to ensure that no module isreverse biased. In addition, or alternatively, a minimum operatingvoltage may be selected for the inverter, below which it is unlikelythat any modules will be reverse biased. That minimum operating voltagemay be adjusted based on other parameters such as the ambienttemperature, the operating current and the calculated or measured solarmodule temperature as well as other information received from outsidesources, such as irradiance for example.

In some embodiments, the high DC voltage solar modules themselves can beshingled, with adjacent solar modules arranged in a partiallyoverlapping manner and optionally electrically interconnected in theiroverlapping regions. Such shingled configurations may optionally be usedfor high voltage solar modules electrically connected in parallel thatprovide a high DC voltage to a string inverter, or for high voltagesolar modules that each comprise a microinverter that converts the solarmodule's high DC voltage to an AC module output. A pair of high voltagesolar modules may be shingled as just described and electricallyconnected in series to provide a desired DC voltage, for example.

Conventional string inverters often are required to have a fairly widerange of potential input voltage (or ‘dynamic range’) because 1) theymust be compatible with different series-connected module stringlengths, 2) some modules in a string may be fully or partially shaded,and 3) changes in ambient temperature and radiation change the modulevoltage. In systems employing parallel architecture as described hereinthe length of the string of parallel-connected solar modules does notaffect voltage. Further, for the case where some modules are partiallyshaded and some are not one can decide to operate the system at thevoltage of the non-shaded modules (e.g., as described above). Thereforethe input voltage range of an inverter in a parallel-architecture systemmay need only accommodate the ‘dynamic range’ of factor #3-temperatureand radiation changes. Because this is less, for example about 30% ofthe conventional dynamic range required of inverters, inverters employedwith parallel architecture systems as described herein may have anarrower range of MPPT (maximum power point tracking), for examplebetween about 250 volts at standard conditions and about 175 volts athigh temperature and low radiation, or for example between about 450volts at standard conditions and about 350 volts at high temperature andlow radiation (in which case 450 volts MPPT operation may correspond toa Voc under 600 volts in lowest temperature operation). In addition, asdescribed above the inverters may receive enough DC voltage to convertdirectly to AC without a boost phase. Consequently, string invertersemployed with parallel architecture systems as described herein may besimpler, of lower cost, and operate at higher efficiencies than stringinverters employed in conventional systems.

For both microinverters and string inverters employed with the highvoltage direct current shingled solar cell modules described herein, toeliminate a DC boost requirement of the inverter it may be preferable toconfigure the solar module (or short series-connected string of solarmodules) to provide an operating (e.g., maximum power point Vmp) DCvoltage above the peak-to-peak of the AC. For example, for 120 V AC,peak-to peak is sqrt(2)*120V=170V. Hence the solar modules might beconfigured to provide a minimal Vmp of about 175 V, for example. The Vmpat standard conditions might then be about 212 V (assuming 0.35%negative voltage temperature coefficient and maximal operatingtemperature of 75° C.), and the Vmp at the lowest temperature operatingcondition (e.g., −15° C.) would then be about 242 V, and hence the Vocbelow about 300 V (depending on the module fill factor). For split phase120 V AC (or 240 V AC) all of these numbers double, which is convenientas 600 V DC is the maximum permitted in the US for many residentialapplications. For commercial applications, requiring and permittinghigher voltages, these numbers may be further increased.

A high voltage shingled solar cell module as described herein may beconfigured to operate at >600 Voc or >1000 Voc, in which case the modulemay comprise integrated power electronics that prevent the externalvoltage provided by the module from exceeding code requirements. Such anarrangement may enable the operating V_(mp) to be sufficient for splitphase 120 V (240 V, requiring about 350 V) without a problem of Voc atlow temperatures exceeding 600 V.

When a building's connection to the electricity grid is disconnected,for example by firefighters, solar modules (e.g., on the building roof)providing electricity to the building can still generate power if thesun is shining. This raises a concern that such solar modules can keepthe roof ‘live’ with a dangerous voltage after disconnection of thebuilding from the grid. To address this concern, high voltage directcurrent shingled solar cell modules described herein may optionallyinclude a disconnect, for example in or adjacent to a module junctionbox. The disconnect may be a physical disconnect or a solid statedisconnect, for example. The disconnect may be configured for example tobe “normally off”, so that when it loses a certain signal (e.g., fromthe inverter) it disconnects the solar module's high voltage output fromthe roof circuit. The communication to the disconnect may be, forexample, over the high voltage cables, through a separate wire, orwireless.

A significant advantage of shingling for high-voltage solar modules isheat spreading between solar cells in a shingled super cell. Applicantshave discovered that heat may be readily transported along a siliconsuper cell through thin electrically and thermally conductive bondsbetween adjacent overlapping silicon solar cells. The thickness of theelectrically conductive bond between adjacent overlapping solar cellsformed by the electrically conductive bonding material, measuredperpendicularly to the front and rear surfaces of the solar cells, maybe for example less than or equal to about 200 microns, or less than orequal to about 150 microns, or less than or equal to about 125 microns,or less than or equal to about 100 microns, or less than or equal toabout 90 microns, or less than or equal to about 80 microns, or lessthan or equal to about 70 microns, or less than or equal to about 60microns, or less than or equal to about 50 microns, or less than orequal to about 25 microns. Such a thin bond reduces resistive loss atthe interconnection between cells, and also promotes flow of heat alongthe super cell from any hot spot in the super cell that might developduring operation. The thermal conductivity of the bond between solarcells may be, for example, ≧about 1.5 Watts/(meter K). Further, therectangular aspect ratio of the solar cells typically employed hereinprovides extended regions of thermal contact between adjacent solarcells.

In contrast, in conventional solar modules employing ribboninterconnects between adjacent solar cells, heat generated in one solarcell does not readily spread through the ribbon interconnects to othersolar cells in the module. That makes conventional solar modules moreprone to developing hot spots than are solar modules described herein.

Furthermore, the current through a super cell in the solar modulesdescribed herein is typically less than that through a string ofconventional solar cells, because the super cells described herein aretypically formed by shingling rectangular solar cells each of which hasan active area less than (for example, ⅙) that of a conventional solarcell.

As a consequence, in the solar modules disclosed herein less heat isdissipated in a solar cell reverse biased at the breakdown voltage, andthe heat may readily spread through the super cell and the solar modulewithout creating a dangerous hot spot.

Several additional and optional features may make high voltage solarmodules employing super cells as described herein even more tolerant toheat dissipated in a reverse biased solar cell. For example, the supercells may be encapsulated in a thermoplastic olefin (TPO) polymer. TPOencapsulants are more photo-thermal stable than standard ethylene-vinylacetate (EVA) encapsulants. EVA will brown with temperature andultraviolet light and lead to hot spot issues created by currentlimiting cells. Further, the solar modules may have a glass-glassstructure in which the encapsulated super cells are sandwiched between aglass front sheet and a glass back sheet. Such a glass-glass structureenables the solar module to safely operate at temperatures greater thanthose tolerated by a conventional polymer back sheet. Further still,junction boxes, if present, may be mounted on one or more edges of asolar module, rather than behind the solar module where a junction boxwould add an additional layer of thermal insulation to the solar cellsin the module above it.

Applicants have therefore recognized that high voltage solar modulesformed from super cells as described herein may employ far fewer bypassdiodes than in conventional solar modules, because heat flow through thesuper cells may allow a module to operate without significant risk withone or more solar cells reverse biased. For example, in some variationshigh voltage solar modules as described herein employ less than onebypass diode per 25 solar cells, less than one bypass diode per 30 solarcells, less than one bypass diode per 50 solar cell, less than onebypass diode per 75 solar cells, less than one bypass diode per 100solar cells, only a single bypass diode, or no bypass diode.

Referring now to FIGS. 61A-61C, example high voltage solar modulesutilizing bypass diodes are provided. When a portion of a solar moduleis shaded, damage to the module may be prevented or reduced through theuse of bypass diodes. For the example solar module 4700 shown in FIG.61A, 10 super cells 100 are connected in series. As illustrated, the 10super cells are arranged in parallel rows. Each super cell contains 40series connected solar cells 10, where each of the 40 solar cells ismade from approximately ⅙ of a square or pseudo-square, as describedherein. Under normal unshaded operation, current flows in from junctionbox 4716 through each of the super cells 100 connected in series throughconnectors 4715, and then current flows out through junction box 4717.Optionally, a single junction box may be used instead of separatejunction boxes 4716 and 4717, so that current returns to one junctionbox. The example shown in FIG. 61A shows an implementation withapproximately one bypass diode per super cell. As shown, a single bypassdiode is electrically connected between a pair of neighboring supercells at a point approximately midway along the super cells (e.g., asingle bypass diode 4901A is electrically connected between the 22^(nd)solar cell of the first super cell and its neighboring solar cell in thesecond super cell, a second bypass diode 4901B is electrically connectedbetween the second super cell and the third super cell, and so forth).The first and last strings of cells have only approximately half thenumber of solar cells in a super cell per bypass diode. For the exampleshown in FIG. 61A, the first and last strings of cells include only 22cells per bypass diode. The total number of bypass diodes (11) for thevariation of high voltage solar module illustrated in FIG. 61A is equalto the number of super cells plus 1 additional bypass diode.

Each bypass diode may be incorporated into a flex circuit, for example.Referring now to FIG. 61B, an expanded view of a bypass diode connectedregion of two neighboring super cells is shown. The view for FIG. 61B isfrom the non-sunny side. As shown, two solar cells 10 on neighboringsuper cells are electrically connected using a flex circuit 4718comprising a bypass diode 4720. Flex circuit 4718 and bypass diode 4720are electrically connected to the solar cells 10 using contact pads 4719located on the rear surfaces of the solar cells. (See also furtherdiscussion below of the use of hidden contact pads to provide hiddentaps to bypass diodes.) Additional bypass diode electrical connectionschemes may be employed to reduce the number of solar cells per bypassdiode. One example is illustrated in FIG. 61C. As shown, one bypassdiode is electrically connected between each pair of neighboring supercells approximately midway along the super cells. Bypass diode 4901A iselectrically connected between neighboring solar cells on the first andsecond super cells, bypass diode 4901B is electrically connected betweenneighboring solar cells on the second and third super cells, bypassdiode 4901C is electrically connected between neighboring solar cells onthe third and fourth super cells, and so forth. A second set of bypassdiodes may be included to reduce the number solar cells that will bebypassed in the event of partial shade. For example, a bypass diode4902A is electrically connected between the first and second super cellsat an intermediate point between bypass diodes 4901A and 4901B, a bypassdiode 4902B is electrically connected between the second and third supercells at an intermediate point between bypass diodes 4901B and 4901C,and so forth, reducing the number of cells per bypass diode. Optionally,yet another set of bypass diodes may be electrically connected tofurther reduce the number of solar cells to be bypassed in the event ofpartial shade. Bypass diode 4903A is electrically connected between thefirst and second super cells at an intermediate point between bypassdiodes 4902A and 4901B, bypass diode 4903B is electrically connectedbetween second and third super cells at an intermediate point betweenbypass diodes 4902B and 4901C, further reducing the number of cells perbypass diode. This configuration results in a nested configuration ofbypass diodes, which allows small groups of cells to be bypassed duringpartial shading. Additional diodes may be electrically connected in thismanner until a desired number of solar cells per bypass diode isachieved, e.g., about 8, about 6, about 4, or about 2 per bypass diode.In some modules, about 4 solar cells per bypass diode is desired. Ifdesired, one or more of the bypass diodes illustrated in FIG. 61C may beincorporated into hidden flexible interconnect as illustrated in FIG.61B.

This specification discloses solar cell cleaving tools and solar cellcleaving methods that may be used, for example, to separateconventionally sized square or pseudo square solar cells into aplurality of narrow rectangular or substantially rectangular solarcells. These cleaving tools and methods apply a vacuum between bottomsurfaces of the conventionally sized solar cells and a curved supportingsurface to flex the conventionally sized solar cells against the curvedsupporting surface and thereby cleave the solar cells along previouslyprepared scribe lines. An advantage of these cleaving tools and cleavingmethods is that they do not require physical contact with the uppersurfaces of the solar cells. Consequently, these cleaving tools andmethods may be employed to cleave solar cells comprising soft and/oruncured materials on their upper surfaces that could be damaged byphysical contact. In addition, in some variations these cleaving toolsand cleaving methods may require contact with only portions of thebottom surfaces of the solar cells. In such variations these cleavingtools and methods may be employed to cleave solar cells comprising softand/or uncured materials on portions of their bottom surfaces notcontacted by the cleaving tool.

For example, one solar cell manufacturing method utilizing the cleavingtools and methods disclosed herein comprises laser scribing one or morescribe lines on each of one or more conventionally sized silicon solarcells to define a plurality of rectangular regions on the silicon solarcells, applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells, andapplying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side. The conductiveadhesive bonding material may be applied to the conventionally sizedsilicon solar cells either before or after the solar cells are laserscribed.

The resulting plurality of rectangular silicon solar cells may bearranged in line with long sides of adjacent rectangular silicon solarcells overlapping in a shingled manner with a portion of theelectrically conductive adhesive bonding material disposed in between.The electrically conductive bonding material may then be cured tothereby bond adjacent overlapping rectangular silicon solar cells toeach other and electrically connect them in series. This process forms ashingled “super cell” as described in the patent applications listedabove in the “Cross Reference To Related Applications”.

Turning now to the figures to better understand the cleaving tools andmethods disclosed herein, FIG. 20A schematically illustrates a side viewof an example apparatus 1050 that may be used to cleave scribed solarcells. In this apparatus, a scribed conventionally sized solar cellwafer 45 is carried by a perforated moving belt 1060 over a curvedportion of a vacuum manifold 1070. As solar cell wafer 45 passes overthe curved portion of the vacuum manifold, a vacuum applied through theperforations in the belt pulls the bottom surface of solar cell wafer 45against the vacuum manifold and thereby flexes the solar cell. Theradius of curvature R of the curved portion of the vacuum manifold maybe selected so that flexing solar cell wafer 45 in this manner cleavesthe solar cell along the scribe lines to form rectangular solar cells10. Rectangular solar cells 10 may, for example, be used in a super cellas illustrated in FIGS. 1 and 2. Solar cell wafer 45 may be cleaved bythis method without contacting the top surface of solar cell wafer 45 towhich the conductive adhesive bonding material has been applied.

Cleaving may be preferentially initiated at one end of a scribe line(i.e., at one edge of solar cell 45) by, for example, arranging for thescribe lines to be oriented at an angle θ to the vacuum manifold so thatfor each scribe line one end reaches the curved portion of the vacuummanifold before the other end. As shown in FIG. 20B, for example, thesolar cells may be oriented with their scribe lines at an angle to thedirection of travel of the belt and to a curved cleaving portion of themanifold oriented perpendicularly to the direction of travel of thebelt. As another example, FIG. 20C shows the cells oriented with theirscribe lines perpendicular to the direction of travel of the belt, andcurved cleaving portion of the manifold oriented at an angle to thedirection of travel of the belt.

Cleaving tool 1050 may utilize, for example, a single perforated movingbelt 1060 having a width perpendicular to its direction of travel aboutequal to the width of solar cell wafer 45. Alternatively, tool 1050 maycomprise two, three, four, or more perforated moving belts 1060 whichmay be arranged side-by-side in parallel and optionally spaced apartfrom each other, for example. Cleaving tool 1050 may utilize a singlevacuum manifold, which may for example have a width perpendicular to thedirection of travel of the solar cells approximately equal to the widthof a solar cell wafer 45. Such a vacuum manifold may be employed, forexample, with a single full width perforated moving belt 1060 or withtwo or more such belts arranged side-by-side in parallel and optionallyspaced apart from each other, for example.

Cleaving tool 1050 may comprise two or more curved vacuum manifoldsarranged side-by-side in parallel and space apart from each other, witheach vacuum manifold having the same curvature. Such an arrangement maybe employed, for example, with a single full width perforated movingbelt 1060 or with two or more such belts arranged side-by-side inparallel and optionally spaced apart from each other. For example, thetool may comprise a perforated moving belt 1060 for each vacuummanifold. In the latter arrangement the vacuum manifolds and theircorresponding perforated moving belts may be arranged to contact thebottom of the solar cell wafer only along two narrow strips defined bythe widths of the belts. In such cases the solar cell may comprise softmaterials in the region of the bottom surface of the solar cell wafernot contacted by belts without risk of damage to the soft materialsduring the cleaving process.

Any suitable arrangement of perforated moving belts and vacuum manifoldsmay be used in cleaving tool 1050.

In some variations the scribed solar cell wafers 45 comprise uncuredconductive adhesive bonding material and/or other soft materials ontheir top and/or bottom surfaces prior to cleaving using cleaving tool1050. Scribing of the solar cell wafer and application of the softmaterial may have occurred in either order.

FIG. 62A schematically illustrates a side view, and FIG. 62B a top view,of another example cleaving tool 5210 similar to cleaving tool 1050described above. In use of cleaving tool 5210, a conventionally sizedscribed solar cell wafer 45 is placed on a pair of parallel spaced apartperforated belts 5230 which move at constant speed over a pair ofcorresponding parallel and spaced apart vacuum manifolds 5235. Vacuummanifolds 5235 typically have the same curvature. As the wafer travelswith the belts over the vacuum manifolds through a cleaving region 5235Cthe wafer is bent around a cleaving radius defined by curved supportingsurfaces of the vacuum manifolds by the force of the vacuum pulling onthe bottom of the wafer. As the wafer is bent around the cleaving radiusthe scribe lines become cracks that separate the wafer into individualrectangular solar cells. As further described below, the curvature ofthe vacuum manifolds is arranged so that adjacent cleaved rectangularsolar cells are not coplanar and the edges of adjacent cleavedrectangular solar cells consequently do not contact each other after thecleaving process occurs. The cleaved rectangular solar cells may becontinuously unloaded from the perforated belts by any suitable method,several examples of which are described below. Typically, the unloadingmethod further separates adjacent cleaved solar cells from each other toprevent contact between them if they subsequently lie coplanar.

Still referring to FIGS. 62A-62B, each vacuum manifold may comprise forexample a flat region 5235F providing no, low, or high vacuum; anoptional curved transitional region 5235T providing low or high vacuum,or transitioning from low to high vacuum along its length; a cleaveregion 5235C providing a high vacuum; and a tighter radius post cleaveregion 5235PC providing a low vacuum. Belts 5230 transport wafers 45from flat region 5235F into and through transitional region 5235T andthen into cleave region 5235C, where the wafers cleave, and thentransport the resulting cleaved solar cells 10 out of cleave region5235C and into the post cleave region 5235PC.

Flat region 5235F is typically operated at a low vacuum sufficient toconstrain wafers 45 to the belts and vacuum manifolds. The vacuum heremay be low (or absent) to reduce friction and thus the required belttension, and because it is easier to constrain the wafers 45 to a flatsurface than to curved surfaces. The vacuum in flat region 5235F may be,for example, about 1 to about 6 inches of mercury.

Transitional region 5235T provides a transitional curvature from flatregion 5235F to cleave region 5235C. The radius of curvature, or radiiof curvature, in transitional region 5235T are greater than the radiusof curvature in cleave region 5235C. The curve in transitional region5235T may be a portion of an ellipse, for example, but any suitablecurve may be used. Having wafers 45 approach cleave region 5235C throughtransition region 5235T at a shallower change in curvature, rather thantransitioning directly from a flat orientation in region 5235F to thecleaving radius in cleaving region 5235C, helps to ensure that the edgesof wafers 45 do not lift and break vacuum, which might make it difficultto constrain the wafers to the cleave radius in cleave region 5235C. Thevacuum in transitional region 5235T may, for example, be the same as incleave region 5235C, intermediate between that of region 5235F and5235C, or transition along the length of region 5235T between that inregion 5235F and that in region 5235C. The vacuum in transitional region5235T may be, for example, about 2 to about 8 inches of mercury.

Cleave region 5235C may have a varying radius of curvature or,optionally, a constant radius of curvature. Such a constant radius ofcurvature may be, for example, about 11.5 inches, about 12.5 inches, orbetween about 6 inches and about 18 inches. Any suitable range ofcurvature may be used, and may be selected based in part on thethickness of wafer 45 and the depth and geometry of the scribe lines inwafer 45. Typically, the thinner the wafer the shorter the radius ofcurvature required to flex the wafer sufficiently to crack it along ascribe line. The scribe lines may have a depth, for example, of about 60microns to about 140 microns, though any other suitable shallower ordeeper scribe line depth may also be used. Typically, the shallower thescribe the shorter the radius of curvature required to flex the wafersufficiently to crack it along a scribe line. The cross-sectional shapeof the scribe line also affects the required radius of curvature. Ascribe line having a wedge shape or a wedge shaped bottom mayconcentrate stress more effectively than a scribe line having a roundedshape or a rounded bottom. Scribe lines that concentrate stress moreeffectively may not require as tight a radius of curvature in the cleaveregion as scribe lines that concentrate stress less effectively.

The vacuum in cleave region 5235C, at least for one of the two parallelvacuum manifolds, is typically higher than in the other regions toensure that the wafer is properly constrained to the cleaving radius ofcurvature to maintain constant bending stress. Optionally, and asfurther explained below, in this region one manifold may provide ahigher vacuum than the other in order to better control cracking alongthe scribe lines. The vacuum in cleave region 5235C may be, for example,about 4 to about 15 inches of mercury, or about 4 to about 26 inches ofmercury.

Post cleave region 5235PC typically has a tighter radius of curvaturethan cleave region 5235C. This facilitates transferring the cleavedsolar cells from belts 5230 without allowing the fractured surfaces ofadjacent cleaved solar cells to rub or touch (which could cause solarcell failures from cracks or other failure modes). In particular, thetighter radius of curvature provides greater separation between theedges of adjacent cleaved solar cells on the belts. The vacuum in postcleave region 5235PC may be low (e.g., similar to or the same as that inflat region 5235F) because the wafers 45 have already been cleaved intosolar cells 10 so it is no longer necessary to constrain the solar cellsto the curved radius of the vacuum manifolds. Edges of the cleaved solarcells 10 may lift off from belts 5230, for example. Further, it may bedesirable that cleaved solar cells 10 not be overstressed.

The flat, transitional, cleave, and post-cleave regions of the vacuummanifolds may be discrete portions of different curves with their endsmatched. For example, the upper surface of each manifold may comprise aflat planar portion, a portion of an ellipse for the transition region,an arc of circle for the cleave region, and another arc of a circle orportion of an ellipse for the post cleave region. Alternatively, some orall of the curved portion of the upper surface of a manifold maycomprise a continuous geometric function of increasing curvature(decreasing diameter of the osculating circle). Suitable such functionsmay include but are not limited to spiral functions such as clothoids,for example, and the natural log function. A clothoid is a curve inwhich the curvature increases linearly along the curve path length. Forexample, in some variations, the transitional, cleave, and post cleaveregions are all part of a single clothoid curve having one end matchedto the flat region. In some other variations, the transitional region isa clothoid curve having one end matched to the flat region and anotherend matched to a cleave region having a circular curvature. In thelatter variations the post cleave region may have, for example, atighter radius circular curvature, or a tighter radius clothoidcurvature.

As noted above and as schematically illustrated in FIG. 62B and FIG.63A, in some variations one manifold provides a high vacuum in cleaveregion 5235C and the other manifold provides a low vacuum in cleaveregion 5235C. The high vacuum manifold fully constrains the end of thewafer it supports to the curvature of the manifold, which providessufficient stress at the end of a scribe line overlying the high vacuummanifold to start a crack along the scribe line. The low vacuum manifolddoes not fully constrain the end of the wafer it supports to thecurvature of the manifold, so the bend radius of the wafer on that sideis not tight enough to create the stress necessary to start a crack inthe scribe line. However, the stress is sufficiently high to propagatethe crack started at the other end of the scribe line overlying the highvacuum manifold. Without some vacuum on the “low vacuum” side topartially and sufficiently constrain that end of the wafer to thecurvature of the manifold, there may be a risk that the crack started onthe opposite “high vacuum” end of the wafer does not propagate all theway across the wafer. In variations as just described one manifold mayoptionally provide a low vacuum along its entire length, from flatregion 5235F through post cleave region 5235PC.

As just described, an asymmetric vacuum arrangement in cleave region5235C provides asymmetric stress along the scribe lines that controlsnucleation and propagation of cracks along the scribe lines. Referringfor example to FIG. 63B, if instead the two vacuum manifolds provideequal (e.g., high) vacuums in cleave regions 5235C, cracks may nucleateat both ends of the wafer, propagate toward each other, and meetsomewhere in a central region of the wafer. Under these circumstancesthere is a risk that the cracks are not in line with each other and thatthey therefore produce a potential mechanical failure point in theresulting cleaved cells where the cracks meet.

As an alternative to the asymmetric vacuum arrangement described above,or in addition to it, cleaving may be preferentially initiated at oneend of a scribe line by arranging for one end of the scribe line toreach the cleave region of the manifolds before the other. This may beaccomplished, for example, by orienting the solar cell wafers at anangle to the vacuum manifolds as described above with respect to FIG.20B. Alternatively, the vacuum manifolds may be arranged so that thecleave region of one of the two manifolds is further along the belt paththan the cleave region of the other vacuum manifold. For example, twovacuum manifolds having the same curvature may be slightly offset in thedirection of travel of the moving belt so that the solar cell wafersreach the cleave region of one manifold before reaching the cleaveregion of the other vacuum manifold.

Referring now to FIG. 64, in the illustrated example each vacuummanifold 5235 comprises through holes 5240 arranged in line down thecenter of a vacuum channel 5245. As shown in FIGS. 65A-65B, vacuumchannel 5245 is recessed into an upper surface of the manifold thatsupports a perforated belt 5230. Each vacuum manifold also comprisescenter pillars 5250 positioned between through holes 5240 and arrangedin line down the center of vacuum channel 5245. Center pillars 5250effectively separate vacuum channel 5245 into two parallel vacuumchannels on either side of the row of center pillars. Center pillars5250 also provide support for belt 5230. Without center pillars 5250,belt 5230 would be exposed to a longer unsupported region and couldpotentially be sucked down toward through holes 5240. This could resultin three-dimensional bending of wafers 45 (bending with the cleaveradius and perpendicular to the cleave radius), which could damage thesolar cells and interfere with the cleaving process.

As shown in FIGS. 65A-65B and FIGS. 66-67, in the illustrated examplethrough holes 5240 communicate with a low vacuum chamber 5260L (flatregion 5235F and transition region 5235T in FIG. 62A), with a highvacuum chamber 5260H (cleave region 5235C in FIG. 62A), and with anotherlow vacuum chamber 5260L (post cleave region 5235PC in FIG. 62A). Thisarrangement provides a smooth transition between low vacuum and highvacuum regions in vacuum channel 5245. Through holes 5240 provide enoughflow resistance so that if the region to which a hole corresponds isleft fully open the air flow will not completely bias to that one hole,allowing other regions to maintain vacuum. Vacuum channel 5245 helps toensure that the vacuum belt holes 5255 will always have vacuum and willnot be in a dead spot when positioned between the through holes 5240.

Referring again to FIGS. 65A-65B and also to FIG. 67, perforated belts5230 may comprise, for example, two rows of holes 5255 optionallyarranged such that leading and trailing edges 527 of a wafer 45 or acleaved solar cell 10 are always under vacuum as the belt progressesalong the manifold. In particular, the staggered arrangement of holes5255 in the illustrated example ensures that the edges of a wafer 45 ora cleaved solar cell 10 always overlap at least one hole 5255 in eachbelt 5230. This helps to prevent edges of a wafer 45 or cleaved solarcell 10 from lifting away from belt 5230 and manifold 5235. Any othersuitable arrangement of holes 5255 may also be used. In some variations,the arrangement of holes 5255 does not ensure that the edges of a wafer45 or a cleaved solar cell 10 are always under vacuum.

Perforated moving belts 5230 in the illustrated example of cleaving tool5210 contact the bottom of solar cell wafer 45 only along two narrowstrips defined by the widths of the belts along the lateral edges of thesolar cell wafer. Consequently, the solar cell wafer may comprise softmaterials such as uncured adhesives, for example, in the region of thebottom surface of the solar cell wafer not contacted by belts 5230without risk of damage to the soft materials during the cleavingprocess.

In alternative variations cleaving tool 5210 may utilize, for example, asingle perforated moving belt 5230 having a width perpendicular to itsdirection of travel about equal to the width of solar cell wafer 45,rather than two perforated moving belts as just described.Alternatively, cleaving tool 5210 may comprise three, four, or moreperforated moving belts 5230 which may be arranged side-by-side inparallel and optionally spaced apart from each other. Cleaving tool 5210may utilize a single vacuum manifold 5235 which may for example have awidth perpendicular to the direction of travel of the solar cellsapproximate equal to the width of a solar cell wafer 45. Such a vacuummanifold may be employed, for example, with a single full widthperforated moving belt 5230 or with two or more such belts arrangedside-by-side in parallel and optionally spaced apart from each other.Cleaving tool 5210 may comprise, for example, a single perforated movingbelt 5230 supported along opposite lateral edges by two curved vacuummanifolds 5235 arranged side-by-side in parallel and space apart fromeach other, with each vacuum manifold having the same curvature.Cleaving tool 5210 may comprise three or more curved vacuum manifolds5235 arranged side-by-side in parallel and space apart from each other,with each vacuum manifold having the same curvature. Such an arrangementmay be employed, for example, with a single full width perforated movingbelt 5230 or with three or more such belts arranged side-by-side inparallel and optionally spaced apart from each other. The cleaving toolmay comprise a perforated moving belt 5230 for each vacuum manifold, forexample.

Any suitable arrangement of perforated moving belts and vacuum manifoldsmay be used in cleaving tool 5210.

As noted above, in some variations the scribed solar cell wafers 45cleaved with cleaving tool 5210 comprise uncured conductive adhesivebonding material and/or other soft materials on their top and/or bottomsurfaces prior to cleaving. Scribing of the solar cell wafer andapplication of the soft material may have occurred in either order.

Perforated belts 5230 in cleaving tool 5210 (and perforated belts 1060in cleaving tool 1050) may transport solar cell wafers 45 at a speed of,for example, about 40 millimeters/second (mm/s) to about 2000 mm/s orgreater, or about 40 mm/s to about 500 mm/s or greater, or about 80 mm/sor greater. Cleaving of solar cell wafers 45 may be easier at higherthan at lower speeds.

Referring now to FIG. 68, once cleaved there will be some separationbetween leading and trailing edges 527 of adjacent cleaved cells 10 dueto the geometry of bending around a curve, which creates a wedge shapedgap between adjacent cleaved solar cells. If the cleaved cells areallowed to return to a flat coplanar orientation without firstincreasing the separation between cleaved cells, there is thepossibility that edges of adjacent cleaved cells could contact anddamage each other. Therefore it is advantageous to remove the cleavedcells from belts 5230 (or belts 1060) while they are still supported bya curved surface.

FIGS. 69A-69G schematically illustrate several apparatus and methods bywhich cleaved solar cells may be removed from belts 5230 (or belts 1060)and delivered to one or more additional moving belts or moving surfaceswith increased separation between the cleaved solar cells. In theexample of FIG. 69A, cleaved solar cells 10 are collected from belts5230 by one or more transfer belts 5265, which move faster than belts5230 and therefore increase the separation between cleaved solar cells10. Transfer belts 5265 may be positioned between the two belts 5230,for example. In the example of FIG. 69B, cleaved wafers 10 are separatedby sliding down a slide 5270 positioned between the two belts 5230. Inthis example, belts 5230 advance each cleaved cell 10 into a low vacuum(e.g., no vacuum) region of manifolds 5235 to release the cleaved cellto slide 5270, while the uncleaved portion of wafer 45 is still held bybelts 5230. Providing an air cushion between the cleaved cell 10 and theslide 5270 helps to ensure that both the cell and the slide are notabraded during the operation, and also allows cleaved cells 10 to slidemore quickly away from wafer 45 thereby allowing for quicker cleave beltoperation speeds.

In the example of FIG. 69C, carriages 5275A in a rotating “Ferris Wheel”arrangement 5275 transfer cleaved solar cells 10 from belts 5230 to oneor more belts 5280.

In the example of FIG. 69D, rotating roller 5285 applies a vacuumthrough actuators 5285A to pick up cleaved solar cells 10 from belts5230 and place them on belts 5280.

In the example of FIG. 69E, a carriage actuator 5290 comprises acarriage 5290A and an extendable and retractable actuator 5290B mountedon the carriage. Carriage 5290A translates back and forth to positionactuator 5290B to remove a cleaved solar cell 10 from belts 5230 andthen to position actuator 5290B to place the cleaved solar cell on belts5280.

In the example of FIG. 69F, a carriage track arrangement 5295 comprisescarriages 5295A attached to a moving belt 5300 which positions carriages5295A to remove cleaved solar cells 10 from belts 5230 and thenpositions carriages 5295A to place cleaved solar cells 10 on belts 5280,the latter occurring as the carriages fall or pull away from belt 5280due to the path of belt 5230.

In the example of FIG. 69G, an inverted vacuum belt arrangement 5305applies a vacuum through one or more moving perforated belts to transfercleaved solar cells 10 from belts 5230 to belts 5280.

FIGS. 70A-70C provide orthogonal views of an additional variation of theexample tool described above with reference to FIGS. 62A-62B and laterfigures. This variation 5310 uses transfer belts 5265, as in the exampleof FIG. 69A, to remove cleaved solar cells 10 from the perforated belts5230 that transport uncleaved wafer 45 into the cleave region of thetool. The perspective views of FIGS. 71A-71B show this variation of thecleaving tool at two different stages of operation. In FIG. 71A anuncleaved wafer 45 is approaching the cleaving region of the tool, andin FIG. 71B the wafer 45 has entered the cleaving region and two cleavedsolar cells 10 have been separated from the wafer and then furtherseparated from each other as they are transported by transfer belts5265.

In addition to features previously described, FIGS. 70A-71B showmultiple vacuum ports 5315 on each manifold. Use of multiple ports permanifold may allow greater control over the variation of vacuum alongthe length of the upper surface of the manifold. For example, differentvacuum ports 5315 may optionally communicate with different vacuumchambers (e.g., 5260L and 5260H in FIG. 66 and FIG. 72B), and/oroptionally be connected to different vacuum pumps, to provide differentvacuum pressures along the manifold. FIGS. 70A-70B also show thecomplete paths of perforated belts 5230, which loop around wheels 5325,upper surfaces of vacuum manifolds 5235, and wheels 5320. Belts 5230 maybe driven by either wheels 5320 or wheels 5325, for example.

FIG. 72A and FIG. 72B show perspective views of a portion of a vacuummanifold 5235 overlaid by a portion of a perforated belt 5230 for thevariation of FIGS. 70A-71B, with FIG. 72A providing a close-up view of aportion of FIG. 72B. FIG. 73A shows a top view of a portion of vacuummanifold 5235 overlaid by a perforated belt 5230, and FIG. 73B shows across-sectional view of the same vacuum manifold and perforated beltarrangement taken along the line C-C indicated in FIG. 73A. As shown inFIG. 73B, the relative orientations of through holes 5240 may vary alongthe length of vacuum manifold so that each through hole is arrangedperpendicularly to the portion of the upper surface of the manifolddirectly above the through hole. FIG. 74A shows another top view of aportion of vacuum manifold 5235 overlaid by a perforated belt 5230, withvacuum chambers 5260L and 5260H shown in phantom views. FIG. 74B shows aclose-up view of a portion of FIG. 74A.

FIGS. 75A-75G show several example hole patterns that may optionally beused for perforated vacuum belts 5230. A common characteristic of thesepatterns is that the straight edge of a wafer 45 or cleaved solar cell10 crossing the pattern perpendicularly to the long axis of the belt atany location on the belt will always overlap at least one hole 5255 ineach belt. The patterns may comprise, for example, two or more rows ofstaggered square or rectangular holes (FIGS. 75A, 75D), two or more rowsof staggered circular holes (FIGS. 75B, 75E, 75G), two or more rows ofangled slots (FIGS. 75C, 75F), or any other suitable arrangement ofholes.

This specification discloses high-efficiency solar modules comprisingsilicon solar cells arranged in an overlapping shingled manner andelectrically connected in series by conductive bonds between adjacentoverlapping solar cells to form super cells, with the super cellsarranged in physically parallel rows in the solar module. A super cellmay comprise any suitable number of solar cells. The super cells mayhave lengths spanning essentially the full length or width of the solarmodule, for example, or two or more super cells may be arrangedend-to-end in a row. This arrangement hides solar cell-to-solar cellelectrical interconnections, and may therefore be used to create avisually appealing solar module with little to no contrast betweenadjacent series connected solar cells.

This specification further discloses cell metallization patterns thatfacilitate stencil printing of metallization onto front (and optionally)rear surfaces of the solar cells. As used herein, “stencil printing” ofcell metallization refers to applying the metallization material (e.g.,a silver paste) onto a solar cell surface through patterned openings inan otherwise impermeable sheet of material. The stencil may be apatterned stainless steel sheet, for example. The patterned openings inthe stencil are entirely free of stencil material, and do not forexample include any mesh or screen. The absence of mesh or screenmaterial in the patterned stencil openings distinguishes “stencilprinting” as used herein from “screen printing”. By contrast, in screenprinting the metallization material is applied onto a solar cell surfacethrough a screen (e.g., mesh) supporting a patterned impermeablematerial. The pattern comprises openings in the impermeable materialthrough which the metallization material is applied to the solar cell.The supporting screen extends across the openings in the impermeablematerial.

Compared to screen printing, stencil printing of cell metallizationpatterns offers numerous advantages including narrower line widths,higher aspect ratio (line height to width), better line uniformity anddefinition, and greater longevity of a stencil compared to a screen.However, stencil printing cannot print ‘islands’ in one pass as would berequired in conventional 3 bus bar metallization designs. Further,stencil printing cannot print in one pass a metallization pattern thatwould require the stencil to include unsupported structures that are notconstrained to lie in the plane of the stencil during printing and mightinterfere with placement and use of the stencil. For example, stencilprinting cannot print in one pass a metallization pattern in whichmetallization fingers arranged in parallel are interconnected by a busbar or other metallization feature running perpendicular to the fingers,because a single stencil for such a design would include unsupportedtongues of sheet material defined by the opening for the bus bar and theopenings for the fingers. The tongues would not be constrained byphysical connections to other portions of the stencil to lie in theplane of the stencil during printing and would likely shift out of planeand distort placement and use of the stencil.

Consequently, attempts at using stencils for printing traditional solarcells require two passes for the front side metallization with twodifferent stencils, or with a stencil printing step in combination witha screen printing step, which increases the total number of print stepsper cell and which also creates a ‘stitching’ issue where the two printsoverlap and result in double height. The stitching complicates furtherprocesses and the extra printing and related steps increase cost.Stencil printing is therefore not common for solar cells.

As further described below, the front surface metallization patternsdescribed herein may comprise an array of fingers (e.g., parallel lines)that are not connected to each other by the front surface metallizationpattern. These patterns can be stencil-printed in one pass with a singlestencil because the required stencil need not include unsupportedportions or structures (e.g., tongues). Such front surface metallizationpatterns may be disadvantageous for standard sized solar cells and forstrings of solar cells in which spaced-apart solar cells areinterconnected by copper ribbons, because the metallization pattern doesnot itself provide for substantial current spreading or electricalconduction perpendicular to the fingers. However, the front surfacemetallization patterns described herein may work well in shingledarrangements of rectangular solar cells as described herein in which aportion of the front surface metallization pattern of a solar cell isoverlapped by and conductively bonded to the rear surface metallizationpattern of an adjacent solar cell. This is because the overlapping rearsurface metallization of the adjacent solar cell may provide for currentspreading and electrical conduction perpendicular to the fingers in thefront surface metallization pattern.

Turning now to the figures for a more detailed understanding of thesolar modules described in this specification, FIG. 1 shows across-sectional view of a string of series-connected solar cells 10arranged in a shingled manner with the ends of adjacent solar cellsoverlapping and electrically connected to form a super cell 100. Eachsolar cell 10 comprises a semiconductor diode structure and electricalcontacts to the semiconductor diode structure by which electric currentgenerated in solar cell 10 when it is illuminated by light may beprovided to an external load.

In the examples described in this specification, each solar cell 10 is arectangular crystalline silicon solar cell having front (sun side)surface and rear (shaded side) surface metallization patterns providingelectrical contact to opposite sides of an n-p junction, the frontsurface metallization pattern is disposed on a semiconductor layer ofn-type conductivity, and the rear surface metallization pattern isdisposed on a semiconductor layer of p-type conductivity. However, othermaterial systems, diode structures, physical dimensions, or electricalcontact arrangements may be used if suitable. For example, the front(sun side) surface metallization pattern may be disposed on asemiconductor layer of p-type conductivity, and the rear (shaded side)surface metallization pattern disposed on a semiconductor layer ofn-type conductivity.

Referring again to FIG. 1, in super cell 100 adjacent solar cells 10 areconductively bonded directly to each other in the region in which theyoverlap by an electrically conductive bonding material that electricallyconnects the front surface metallization pattern of one solar cell tothe rear surface metallization pattern of the adjacent solar cell.Suitable electrically conductive bonding materials may include, forexample, electrically conductive adhesives and electrically conductiveadhesive films and adhesive tapes, and conventional solders.

Referring back to FIG. 2, FIG. 2 shows an example rectangular solarmodule 200 comprising six rectangular super cells 100, each of which hasa length approximately equal to the length of the long sides of thesolar module. The super cells are arranged as six parallel rows withtheir long sides oriented parallel to the long sides of the module. Asimilarly configured solar module may include more or fewer rows of suchside-length super cells than shown in this example. In other variationsthe super cells may each have a length approximately equal to the lengthof a short side of a rectangular solar module, and be arranged inparallel rows with their long sides oriented parallel to the short sidesof the module. In yet other arrangements each row may comprise two ormore super cells, which may be electrically interconnected in series forexample. The modules may have shorts sides having a length, for example,of about 1 meter and long sides having a length, for example, of about1.5 to about 2.0 meters. Any other suitable shapes (e.g., square) anddimensions for the solar modules may also be used. Each super cell inthis example comprises 72 rectangular solar cells each having a widthapproximately equal to ⅙ the width of a 156 millimeter (mm) square orpseudo square wafer and a length of about 156 mm. Any other suitablenumber of rectangular solar cells of any other suitable dimensions mayalso be used.

FIG. 76 shows an example front surface metallization pattern on arectangular solar cell 10 that facilitates stencil printing as describedabove. The front surface metallization pattern may be formed, forexample, from silver paste. In the example of FIG. 76 the front surfacemetallization pattern comprises a plurality of fingers 6015 runningparallel to each other, parallel to the short sides of the solar cell,and perpendicular to the long sides of the solar cell. The front surfacemetallization pattern also comprises a row of optional contact pads 6020running parallel to and adjacent the edge of a long side of the solarcell, with each contact pad 6020 located at the end of a finger 6015.Where present, each contact pad 6020 creates an area for an individualbead of electrically conductive adhesive (ECA), solder, or otherelectrically conductive bonding material used to conductively bond thefront surface of the illustrated solar cell to an overlapping portion ofthe rear surface of an adjacent solar cell. The pads may have circular,square, or rectangular shapes for example, but any suitable pad shapemay be used. As an alternative to using individual beads of electricallyconductive bonding material, a continuous or dashed line of ECA, solder,conductive tape, or other electrically conductive bonding materialdisposed along the edge of a long side of the solar cell mayinterconnect some or all of the fingers as well as bond the solar cellto an adjacent overlapping solar cell. Such a dashed or continuous lineof electrically conductive bonding material may be used in combinationwith conductive pads at the ends of the fingers, or without suchconductive pads.

Solar cell 10 may have, for example, a length of about 156 mm, a widthof about 26 mm, and thus an aspect ratio (length of short side/length oflong side) of about 1:6. Six such solar cells may be prepared on astandard 156 mm×156 mm dimension silicon wafer, then separated (diced)to provide solar cells as illustrated. In other variations, eight solarcells 10 having dimensions of about 19.5 mm×156 mm, and thus an aspectratio of about 1:8, may be prepared from a standard silicon wafer. Moregenerally, solar cells 10 may have aspect ratios of, for example, about1:2 to about 1:20 and may be prepared from standard size wafers or fromwafers of any other suitable dimensions.

Referring again to FIG. 76, the front surface metallization pattern maycomprise, for example, about 60 to about 120 fingers per 156 mm widecell, for example about 90 fingers. Fingers 6015 may have widths of, forexample, about 10 to about 90 microns, for example about 30 microns.Fingers 6015 may have heights perpendicular to the surface of the solarcell of, for example, about 10 to about 50 microns. The finger heightsmay be, for example, about 10 microns or more, about 20 microns or more,about 30 microns or more, about 40 microns or more, or about 50 micronsor more. Pads 6020 may have diameters (circles) or side lengths (squaresor rectangles) of, for example, about 0.1 mm to about 1 mm, for exampleabout 0.5 mm.

The rear surface metallization pattern for rectangular solar cell 10 maycomprise, for example, a row of discrete contact pads, a row ofinterconnected contact pads, or a continuous bus bar running parallel toand adjacent to an edge of a long side of the solar cell. Such contactpads or bus bar are not required, however. If the front surfacemetallization pattern comprises contact pads 6020 arranged along an edgeof one of the long sides of the solar cell, then the row of contact padsor bus bar (if present) in the rear surface metallization pattern isarranged along an edge of the other long side of the solar cell. Therear surface metallization pattern may further comprise a metal backcontact covering substantially all of the remaining rear surface of thesolar cell. The example rear surface metallization pattern of FIG. 77Acomprises a row of discrete contact pads 6025 in combination with ametal back contact 6030 as just described, and the example rear surfacemetallization pattern of FIG. 77B comprises a continuous bus bar 35 incombination with a metal back contact 6030 as just described.

In a shingled super cell the front surface metallization pattern of asolar cell is conductively bonded to an overlapping portion of the rearsurface metallization pattern of an adjacent solar cell. For example, ifthe solar cells comprise front surface metallization contact pads 6020,each contact pad 6020 may be may be aligned with and bonded to acorresponding rear surface metallization contact pad 6025 (if present),or aligned with and bonded to a rear surface metallization bus bar 35(if present), or bonded to metal back contact 6030 (if present) on theadjacent solar cell. This may be accomplished for example with discreteportions (e.g., beads) of electrically conductive bonding materialdisposed on each contact pad 6020, or with a dashed or continuous lineof electrically conductive bonding material running parallel to the edgeof the solar cell and optionally electrically interconnecting two ormore of the contact pads 6020.

If the solar cells lack front surface metallization contact pads 6020,then for example each front surface metallization pattern finger 6015may be aligned with and bonded to a corresponding rear surfacemetallization contact pad 6025 (if present), or bonded to a rear surfacemetallization bus bar 35 (if present), or bonded to metal back contact6030 (if present) on the adjacent solar cell. This may be accomplishedfor example with discrete portions (e.g., beads) of electricallyconductive bonding material disposed on the overlapped end of eachfinger 6015, or with a dashed or continuous line of electricallyconductive bonding material running parallel to the edge of the solarcell and optionally electrically interconnecting two or more of fingers6015.

As noted above, portions of the overlapping rear surface metallizationof the adjacent solar cell, for example a rear surface bus bar 35 and/orback metal contact 6030 if present, may provide for current spreadingand electrical conduction perpendicular to the fingers in the frontsurface metallization pattern. In variations utilizing dashed orcontinuous lines of electrically conductive bonding material asdescribed above, the electrically conductive bonding material mayprovide for current spreading and electrical conduction perpendicular tothe fingers in the front surface metallization pattern. The overlappingrear metallization and/or the electrically conductive bonding materialmay for example carry current to bypass broken fingers or other fingerdisruptions in the front surface metallization pattern.

Rear surface metallization contact pads 6025 and bus bar 35, if present,may be formed for example from silver paste, which may be applied bystencil printing, screen printing, or any other suitable method. Metalback contact 6030 may be formed, for example, from aluminum.

Any other suitable rear surface metallization patterns and materials mayalso be used.

FIG. 78 shows an example front surface metallization pattern on a squaresolar cell 6300 that may be diced to form a plurality of rectangularsolar cells each having the front surface metallization pattern shown inFIG. 76.

FIG. 79 shows an example rear surface metallization pattern on a squaresolar cell 6300 that may be diced to form a plurality of rectangularsolar cells each having the rear surface metallization pattern shown inFIG. 77A.

The front surface metallization patterns described herein may enablestencil printing of the front surface metallization on a standard threeprinter solar cell production line. For example, the production processmay comprise stencil or screen printing silver paste onto the rearsurface of a square solar cell to form rear surface contact pads or arear surface silver bus bar using a first printer, then drying the rearsurface silver paste, then stencil or screen printing an aluminumcontact on the rear surface of the solar cell using a second printer,then drying the aluminum contact, then stencil printing silver pasteonto the front surface of the solar cell to form a complete frontsurface metallization pattern using a single stencil in a singlestenciling step with a third printer, then drying the silver paste, thenfiring the solar cell. These printing and related steps may occur in anyother order, or be omitted, as suitable.

The use of a stencil to print the front surface metallization patternenables the production of narrower fingers than possible with screenprinting, which may improve solar cell efficiency and decrease the useof silver and thus the cost of production. Stencil printing the frontsurface metallization pattern in a single stencil printing step with asingle stencil enables the production of a front surface metallizationpattern having a uniform height, e.g., not exhibiting stitching as mayoccur if multiple stencils or stencil printing in combination withscreen printing are used for overlapping prints to define featuresextending in different directions.

After front and rear surface metallization patterns are formed on thesquare solar cells, each square solar cell may be separated into two ormore rectangular solar cells. This may be accomplished for example bylaser scribing followed by cleaving, or by any other suitable method.The rectangular solar cells may then be arranged in an overlappingshingled manner and conductively bonded to each other as described aboveto form a super cell. This specification discloses methods formanufacturing solar cells with reduced carrier recombination losses atedges of the solar cell, e.g., without cleaved edges that promotecarrier recombination. The solar cells may be silicon solar cells, forexample, and more particularly may be HIT silicon solar cells. Thisspecification also discloses shingled (overlapping) super cellarrangements of such solar cells. The individual solar cells in such asuper cell may have narrow rectangular geometries (e.g., strip-likeshapes), with the long sides of adjacent solar cells arranged tooverlap.

A major challenge to the cost-effective implementation of highefficiency solar cells such as HIT solar cells is the conventionallyperceived need for large amounts of metal to carry a large current fromone such high efficiency solar cell to an adjacent series-connected highefficiency solar cell. Dicing such high efficiency solar cells intonarrow rectangular solar cell strips, and then arranging the resultingsolar cells in an overlapping (shingled) pattern with conductive bondsbetween the overlapping portions of adjacent solar cells to form aseries-connected string of solar cells in a super cell, presents anopportunity to reduce module cost through process simplification. Thisis because tabbing process steps conventionally required to interconnectadjacent solar cells with metal ribbons may be eliminated. Thisshingling approach may also improve module efficiency by reducing thecurrent through the solar cells (because the individual solar cellstrips may have smaller than conventional active areas) and by reducingthe current path length between adjacent solar cells, both of which tendto reduce resistive loss. The reduced current may also allowsubstitution of less expensive but more resistive conductors (e.g.,copper) for more expensive but less resistive conductors (e.g., silver)without significant loss in performance. In addition, this shinglingapproach may reduce inactive module area by eliminating interconnectribbons and related contacts from the front surfaces of the solar cells.

Conventionally sized solar cells may have, for example, substantiallysquare front and rear surfaces with dimensions of about 156 millimeters(mm)×about 156 mm. In the shingling scheme just described, such a solarcell is diced into two or more (e.g., two to twenty) 156 mm long solarcell strips. A potential difficulty with this shingling approach is thatdicing a conventionally sized solar cell into thin strips increases thecell edge length per active area of solar cell compared to aconventionally sized solar cell, which can degrade performance due tocarrier recombination at the edges.

For example, FIG. 80 schematically illustrates the dicing of a HIT solarcell 7100 having front and rear surface dimensions of about 156 mm×about156 mm into several solar cell strips (7100 a, 7100 b, 7100 c, and 7100d) each of which has narrow rectangular front and rear surfaces withdimensions of about 156 mm×about 40 mm. (The long 156 mm sides of thesolar cell strips extend into the page). In the illustrated example HITcell 7100 comprises an n-type monocrystalline base 5105, which may forexample have a thickness of about 180 microns and front and rear squaresurfaces with dimensions of about 156 mm×about 156 mm. An about 5nanometer (nm) thick layer of intrinsic amorphous Si:H (a-Si:H) and anabout 5 nm thick layer of n+ doped a-Si:H (both layers togetherindicated by reference numeral 7110) are disposed on the front surfaceof crystalline silicon base 7105. An about 65 nm thick film 5120 of atransparent conductive oxide (TCO) is disposed on a-Si:H layers 7110.Conductive metal gridlines 7130 disposed on TCO layer 7120 provideelectrical contact to the front surface of the solar cell. An about 5 nmthick layer of intrinsic a-Si:H and an about 5 nm thick layer of p+doped a-Si:H (both layers together indicated by reference numeral 7115)are disposed on the rear surface of crystalline silicon base 7105. Anabout 65 nm thick film 7125 of a transparent conductive oxide (TCO) isdisposed on a-Si:H layers 7115, and conductive metal gridlines 7135disposed on TCO layer 7125 provide electrical contact to the rearsurface of the solar cell. (The dimensions and materials cited above areintended to be exemplary rather than limiting, and may be varied assuitable).

Still referring to FIG. 80, if HIT solar cell 7100 is cleaved byconventional methods to form strip solar cells 7100 a, 7100 b, 7100 c,and 7100 d, newly formed cleaved edges 7140 are not passivated. Thesenon-passivated edges contain a high density of dangling chemical bonds,which promote carrier recombination and reduce the performance of thesolar cells. In particular, the cleaved surface 7145 that exposes then-p junction and the cleaved surface that exposes the heavily dopedfront surface field (in layers 7110) are not passivated and maysignificantly promote carrier recombination. Further, if conventionallaser cutting or laser scribing processes are used in dicing solar cell7100, thermal damage such as re-crystallization 7150 of amorphoussilicon may occur on the newly formed edges. As a result of thenon-passivated edges and the thermal damage, if conventionalmanufacturing processes are used the new edges formed on cleaved solarcells 7100 a, 7100 b, 7100 c, and 7100 d may be expected to reduce theshort-circuit current, the open-circuit voltage, and the pseudo fillfactor of the solar cells. This amounts to a significant reduction inperformance of the solar cells.

The formation of recombination-promoting edges during dicing of aconventionally sized HIT solar cell into narrower solar cell strips maybe avoided with the method illustrated in FIGS. 85A-85J. This methoduses isolation trenches on the front and rear surfaces of theconventionally sized solar cell 7100 to electrically isolate the p-njunction and the heavy doped front surface field from the cleaved edgesthat might otherwise act as recombination sites for minority carriers.The trench edges are not defined by conventional cleaving, but insteadby chemical etching or laser patterning, followed by deposition of apassivation layer such as a TCO that passivates both front and reartrenches. Compared with the heavy doped regions, the base doping issufficiently low that the probability of electrons in the junctionreaching unpassivated cut edges of the base is small. In addition, akerf-less wafer dicing technique, Thermal Laser Separation (TLS), may beused to cut the wafers, avoiding potential thermal damage.

In the example illustrated in FIGS. 85A-85J, the starting material is anabout 156 mm square n-type mono-crystalline silicon as-cut wafer, whichmay have a bulk resistivity of for example about 1 to about 3ohm-centimeters and may be for example about 180 microns thick. (Wafer7105 forms the base of the solar cells).

Referring to FIG. 81A, the as-cut cut wafer 7105 is conventionallytexture-etched, acid cleaned, rinsed, and dried.

Next, in FIG. 81B an about 5 nm thick intrinsic a-Si:H layer and anabout 5 nm thick doped n+ a-Si:H layer (both layers together indicatedby reference numeral 7110) are deposited on the front surface of wafer7105 by plasma enhanced chemical vapor deposition (PECVD), for example,at a temperature of about 150° C. to about 200° C., for example.

Next, in FIG. 81C an about 5 nm thick intrinsic a-Si:H layer and anabout 5 nm thick doped p+ a-Si:H layer (both layers together indicatedby reference numeral 7115) are deposited on the rear surface of wafer7105, by PECVD, for example, at a temperature of about 150° C. to about200° C., for example.

Next, in FIG. 81D the front a-Si:H layers 7110 are patterned to formisolation trenches 7112. Isolation trenches 7112 typically penetratelayers 7110 to reach wafer 7105 and may have widths of, for example,about 100 microns to about 1000 microns, for example about 200 microns.Typically the trenches have the smallest widths that may be used,depending on the accuracy of the patterning techniques and thesubsequently applied cleaving techniques. Patterning of trenches 7112may be accomplished, for example, using laser patterning or chemicaletching (e.g., inkjet wet patterning).

Next, in FIG. 81E the rear a-Si:H layers 7115 are patterned to formisolation trenches 7117. Similarly to isolation trenches 7112, isolationtrenches 7117 typically penetrate layers 7115 to reach wafer 7105 andmay have widths of, for example, about 100 microns to about 1000microns, for example about 200 microns. Patterning of trenches 7117 maybe accomplished, for example, using laser patterning or chemical etching(e.g., inkjet wet patterning). Each trench 7117 is in line with acorresponding trench 7112 on the front surface of the structure.

Next, in FIG. 81F an about 65 nm thick TCO layer 7120 is deposited onthe patterned front a-Si:H layers 7110. This may be accomplished byphysical vapor deposition (PVD) or by ion-plating, for example. TCOlayer 7120 fills trenches 7112 in a-Si:H layers 7110 and coats the outeredges of layers 7110, thereby passivating the surfaces of layers 7110.TCO layer 7120 also functions as an antireflection coating.

Next, in FIG. 81G an about 65 nm thick TCO layer 7125 is deposited onthe patterned rear a-Si:H layers 7115. This may be accomplished by PVDor by ion-plating, for example. TCO layer 7125 fills trenches 7117 ina-Si:H layers 7115 and coats the outer edges of layers 115, therebypassivating the surfaces of layers 7115. TCO layer 7125 also functionsas an antireflection coating.

Next, in FIG. 81H conductive (e.g., metal) front surface grid lines 7130are screen printed onto TCO layer 7120. Grid lines 7130 may be formedfrom low temperature silver pastes, for example.

Next, in FIG. 81I conductive (e.g., metal) rear surface grid lines 7135are screen printed onto TCO layer 7125. Grid lines 7135 may be formedfrom low temperature silver pastes, for example.

Next, after deposition of grid lines 7130 and grid lines 7135, the solarcell is cured at a temperature of about 200° C. for about 30 minutes,for example.

Next, in FIG. 81J the solar cell is separated into solar cell strips7155 a, 7155 b, 7155 c, and 7155 d by dicing the solar cell at thecenters of the trenches. Dicing may be accomplished for example usingconventional laser scribing and mechanical cleaving at the center of thetrenches to cleave the solar cell in line with the trenches.Alternatively, dicing may be accomplished using a Thermal LaserSeparation process (as developed by Jenoptik AG, for example) in whichlaser-induced heating at the centers of the trenches induces mechanicalstress that leads to cleaving of the solar cell in line with thetrenches. The latter approach may avoid thermal damage to edges of thesolar cells.

The resulting strip solar cells 7155 a-7155 d differ from strip solarcells 7100 a-7100 d shown in FIG. 80. In particular, the edges of a-Si:Hlayers 7110 and a-Si:H layers 7115 in solar cells 7140 a-7140 d areformed by etching or laser patterning, not by mechanical cleaving. Inaddition, the edges of layers 7110 and 7115 in solar cells 7155 a-7155 dare passivated by a TCO layer. As a result, solar cells 7140 a-7140 dlack the carrier recombination promoting cleaved edges that are presentin solar cells 7100 a-7100 d.

The method described with respect to FIGS. 81A-81J is intended to beexemplary rather than limiting. Steps described as being performed inparticular sequences may be performed in other sequences or in parallel,as suitable. Steps and material layers may be omitted, added, orsubstituted as suitable. For example, if copper plated metallization isused then additional patterning and seed layer deposition steps may beincluded in the process. Further, in some variations only the fronta-Si:H layers 7110 are patterned to form isolation trenches, and noisolation trenches are formed in the rear a-Si:H layers 7115. In othervariations only the rear a-Si:H layers 7115 are patterned to formisolation trenches, and no isolation trenches are formed in the fronta-Si:H layers 7115. As in the example of FIGS. 81A-81J, in thesevariations as well dicing occurs at the centers of the trenches.

The formation of recombination-promoting edges during dicing of aconventionally sized HIT solar cell into narrower solar cell strips mayalso be avoided with the method illustrated in FIGS. 82A-82J, which alsouses isolation trenches similarly to as employed in the method describedwith respect to FIGS. 81A-81J.

Referring to FIG. 82A, in this example the starting material is again anabout 156 mm square n-type mono-crystalline silicon as-cut wafer 7105,which may have a bulk resistivity of for example about 1 to about 3ohm-centimeters and may be for example about 180 microns thick.

Referring to FIG. 82B, trenches 7160 are formed in the front surface ofwafer 7105. These trenches may have depths of for example, about 80microns to about 150 microns, for example about 90 microns, and may havewidths for example of about 10 microns to about 100 microns. Isolationtrenches 7160 define the geometry of the solar cell strips to be formedfrom wafer 7105. As explained below, wafer 7105 will be cleaved in linewith these trenches. Trenches 7160 may be formed by conventional laserwafer scribing, for example.

Next, in FIG. 82C wafer 7105 is conventionally texture-etched, acidcleaned, rinsed, and dried. The etching typically removes damageinitially present in surfaces of as-cut wafer 7105 or caused duringformation of trenches 7160. The etching may also widen and deepentrenches 7160.

Next, in FIG. 82D an about 5 nm thick intrinsic a-Si:H layer and anabout 5 nm thick doped n+ a-Si:H layer (both layers together indicatedby reference numeral 7110) are deposited on the front surface of wafer7105 by PECVD, for example, at a temperature of about 150° C. to about200° C., for example.

Next, in FIG. 82E an about 5 nm thick intrinsic a-Si:H layer and anabout 5 nm thick doped p+ a-Si:H layer (both layers together indicatedby reference numeral 7115) are deposited on the rear surface of wafer7105, by PECVD, for example, at a temperature of about 150° C. to about200° C., for example.

Next, in FIG. 82F an about 65 nm thick TCO layer 7120 is deposited onthe front a-Si:H layers 7110. This may be accomplished by physical vapordeposition (PVD) or by ion-plating, for example. TCO layer 7120 may filltrenches 7160 and typically coats the walls and bottoms of trenches 7160and the outer edges of layers 7110, thereby passivating the coatedsurfaces. TCO layer 7120 also functions as an antireflection coating.

Next, in FIG. 82G an about 65 nm thick TCO layer 7125 is deposited onthe rear a-Si:H layers 7115. This may be accomplished by PVD or byion-plating, for example. TCO layer 7125 passivates the surfaces (e.g.,including the outer edges) of layers 7115 and also functions as anantireflection coating.

Next, in FIG. 82H conductive (e.g., metal) front surface grid lines 7130are screen printed onto TCO layer 7120. Grid lines 7130 may be formedfrom low temperature silver pastes, for example.

Next, in FIG. 82I conductive (e.g., metal) rear surface grid lines 7135are screen printed onto TCO layer 7125. Grid lines 7135 may be formedfrom low temperature silver pastes, for example.

Next, after deposition of grid lines 7130 and grid lines 7135, the solarcell is cured at a temperature of about 200° C. for about 30 minutes,for example.

Next, in FIG. 82J the solar cell is separated into solar cell strips7165 a, 7165 b, 7165 c, and 7165 d, by dicing the solar cell at thecenters of the trenches. Dicing may be accomplished for example usingconventional mechanical cleaving at the center of the trenches to cleavethe solar cell in line with the trenches. Alternatively, dicing may beaccomplished using a Thermal Laser Separation process as describedabove, for example.

The resulting strip solar cells 7165 a-7165 d differ from strip solarcells 7100 a-7100 d shown in FIG. 80. In particular, the edges of a-Si:Hlayers 7110 in solar cells 7165 a-7165 d are formed by etching, not bymechanical cleaving. In addition, the edges of layers 7110 in solarcells 7165 a-7165 d are passivated by a TCO layer. As a result, solarcells 7165 a-7165 d lack carrier recombination promoting cleaved edgesthat are present in solar cells 7100 a-7100 d.

The method described with respect to FIGS. 82A-82J is intended to beexemplary rather than limiting. Steps described as being performed inparticular sequences may be performed in other sequences or in parallel,as suitable. Steps and material layers may be omitted, added, orsubstituted as suitable. For example, if copper plated metallization isused then additional patterning and seed layer deposition steps may beincluded in the process. Further, in some variations trenches 7160 maybe formed in the rear surface of wafer 7105 rather than in the frontsurface of wafer 7105.

The methods described above with respect to FIGS. 81A-81J and 86A-86Jare applicable to both n-type and p-type HIT solar cells. The solarcells can be front emitter or rear emitter. It may be preferable toapply the separation process on the side without the emitter. Further,the use of isolation trenches and passivation layers as described aboveto reduce recombination on cleaved wafer edges is applicable to othersolar cell designs and to solar cells using material systems other thansilicon.

Referring again to FIG. 1, a string of series-connected solar cells 10formed by the methods described above may be advantageously arranged ina shingled manner with the ends of adjacent solar cells overlapping andelectrically connected to form a super cell 100. In super cell 100adjacent solar cells 10 are conductively bonded to each other in theregion in which they overlap by an electrically conducting bondingmaterial that electrically connects the front surface metallizationpattern of one solar cell to the rear surface metallization pattern ofthe adjacent solar cell. Suitable electrically conducting bondingmaterials may include, for example, electrically conducting adhesivesand electrically conducting adhesive films and adhesive tapes, andconventional solders.

Referring again to FIGS. 5A-5B, FIG. 5A shows an example rectangularsolar module 200 comprising twenty rectangular super cells 100, each ofwhich has a length approximately equal to one half the length of theshort sides of the solar module. Super cells are arranged end-to-end inpairs to form ten rows of super cells, with the rows and the long sidesof the super cells oriented parallel to the short sides of the solarmodule. In other variations, each row of super cells may include threeor more super cells. Also, in other variations super cells may bearranged end-to-end in rows, with the rows and the long sides of thesuper cells oriented parallel to the long sides of a rectangular solarmodule or oriented parallel to a side of a square solar module. Further,a solar module may include more or fewer super cells and more or fewerrows of super cells than shown in this example.

Optional gap 210 shown in FIG. 5A may be present to facilitate makingelectrical contact to front surface end contacts of super cells 100along the center line of the solar module, in variations where the supercells in each row are arranged so that at least one of them has a frontsurface end contact on the end of the super cell adjacent to the othersuper cell in the row. In variations in which each row of super cellsincludes three or more super cells, additional optional gaps betweensuper cells may be present to similarly facilitate making electricalcontact to front surface end contacts that are located away from thesides of the solar module.

FIG. 5B shows another example rectangular solar module 300 comprisingten rectangular super cells 100, each of which has a lengthapproximately equal to the length of the short sides of the solarmodule. The super cells are arranged with their long sides orientedparallel to the short sides of the module. In other variations the supercells may have lengths approximately equal to the length of the longsides of a rectangular solar module and be oriented with their longsides parallel to the long sides of the solar module. The super cellsmay also have lengths approximately equal to the length of the sides ofa square solar module, and be oriented with their long sides parallel toa side of the solar module. Further, a solar module may include more orfewer of such side-length super cells than shown in this example.

FIG. 5B also shows what solar module 200 of FIG. 5A looks like whenthere are no gaps between adjacent super cells in the rows of supercells in solar module 200. Any other suitable arrangement of super cells100 in a solar module may also be used.

The following enumerated paragraphs provide additional non-limitingaspects of the disclosure.

1. A solar module comprising:

a series connected string of N≧25 rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts, the solar cells grouped into one or more supercells each of which comprises two or more of the solar cells arranged inline with long sides of adjacent solar cells overlapping andconductively bonded to each other with an electrically and thermallyconductive adhesive;

wherein no single solar cell or group of <N solar cells in the string ofsolar cells is individually electrically connected in parallel with abypass diode.

2. The solar module of clause 1, wherein N is greater than or equal to30.

3. The solar module of clause 1, wherein N is greater than or equal to50.

4. The solar module of clause 1, wherein N is greater than or equal to100.

5. The solar module of clause 1, wherein the adhesive forms bondsbetween adjacent solar cells having a thickness perpendicular to thesolar cells less than or equal to about 0.1 mm and a thermalconductivity perpendicular to the solar cells greater than or equal toabout 1.5 w/m/k.

6. The solar module of clause 1, wherein the N solar cells are groupedinto a single super cell.

7. The solar module of clause 1, wherein the super cells areencapsulated in a polymer.

7A. The solar module of clause 7 wherein the polymer comprises athermoplastic olefin polymer.

7B. The solar module of clause 7 wherein the polymer is sandwichedbetween a glass front sheet and a back sheet.

7C. The solar module of clause 7B wherein the back sheet comprisesglass.

8. The solar module of clause 1, wherein the solar cells are siliconsolar cells.

9. A solar module comprising:

a super cell substantially spanning a full length or width of the solarmodule parallel to an edge of the solar module, the super cellcomprising a series connected string of N rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts arranged in line with long sides of adjacent solarcells overlapping and conductively bonded to each other with anelectrically and thermally conductive adhesive;

wherein no single solar cell or group of <N solar cells in the supercell is individually electrically connected in parallel with a bypassdiode.

10. The solar module of clause 9, wherein N>24.

11. The solar module of clause 9, wherein the super cell has a length inthe direction of current flow of at least about 500 mm.

12. The solar module of clause 9, wherein the super cells areencapsulated in a thermoplastic olefin polymer sandwiched between glassfront and back sheets.

13. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the front surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconductive adhesive bonding material to at least one front surfacecontact pad prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

14. The super cell of clause 13, wherein for each pair of adjacent andoverlapping silicon solar cells, the barrier on the front surface of oneof the silicon solar cells is overlapped and hidden by a portion of theother silicon solar cell, thereby substantially confining the conductiveadhesive bonding material to overlapped regions of the front surface ofthe silicon solar cell prior to curing of the conductive adhesivebonding material during manufacturing of the super cell.

15. The super cell of clause 13, wherein the barrier comprises acontinuous conductive line running parallel to and for substantially thefull length of the first long side, with at least one front surfacecontact pad located between the continuous conductive line and the firstlong side of the solar cell.

16. The super cell of clause 15, wherein the front surface metallizationpattern comprises fingers electrically connected to the at least onefront surface contact pads and running perpendicularly to the first longside, and the continuous conductive line electrically interconnects thefingers to provide multiple conductive paths from each finger to atleast one front surface contact pad.

17. The super cell of clause 13, wherein the front surface metallizationpattern comprises a plurality of discrete contact pads arranged in a rowadjacent to and parallel to the first long side, and the barriercomprises a plurality of features forming separate barriers for eachdiscrete contact pad that substantially confine the conductive adhesivebonding material to the discrete contact pads prior to curing of theconductive adhesive bonding material during manufacturing of the supercell.

18. The super cell of clause 17, wherein the separate barriers abut andare taller than their corresponding discrete contact pads.

19. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the back surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one back surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

20. The super cell of clause 19, wherein the back surface metallizationpattern comprises one or more discrete contact pads arranged in a rowadjacent to and parallel to the second long side, and the barriercomprises a plurality of features forming separate barriers for eachdiscrete contact pad that substantially confine the conductive adhesivebonding material to the discrete contact pads prior to curing of theconductive adhesive bonding material during manufacturing of the supercell.

21. The super cell of clause 20, wherein the separate barriers abut andare taller than their corresponding discrete contact pads.

22. A method of making a string of solar cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis; and

arranging the rectangular silicon solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein the plurality of rectangular silicon solar cells comprises atleast one rectangular solar cell having two chamfered cornerscorresponding to corners or to portions of corners of the pseudo squarewafer, and one or more rectangular silicon solar cells each lackingchamfered corners; and

wherein the spacing between parallel lines along which the pseudo squarewafer is diced is selected to compensate for the chamfered corners bymaking the width perpendicular to the long axis of the rectangularsilicon solar cells that comprise chamfered corners greater than thewidth perpendicular to the long axis of the rectangular silicon solarcells that lack chamfered corners, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

23. A string of solar cells comprising:

a plurality of silicon solar cells arranged in line with end portions ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein at least one of the silicon solar cells has chamfered cornersthat correspond to corners or portions of corners of a pseudo squaresilicon wafer from which it was diced, at least one of the silicon solarcells lacks chamfered corners, and each of the silicon solar cells has afront surface of substantially the same area exposed to light duringoperation of the string of solar cells.

24. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered corners;

removing the chamfered corners from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered corners;

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength; and

arranging the third plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the thirdplurality of rectangular silicon solar cells in series to form a solarcell string having a width equal to the second length.

25. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered cornerscorresponding to corners or portions of corners of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered corners;

arranging the first plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the firstplurality of rectangular silicon solar cells in series; and

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries.

26. A method of making a solar module, the method comprising:

dicing each of a plurality of pseudo square silicon wafers along aplurality of lines parallel to a long edge of the wafer to form from theplurality of pseudo square silicon wafers a plurality of rectangularsilicon solar cells comprising chamfered corners corresponding tocorners of the pseudo square silicon wafers and a plurality ofrectangular silicon solar cells lacking chamfered corners;

arranging at least some of the rectangular silicon solar cells lackingchamfered corners to form a first plurality of super cells each of whichcomprises only rectangular silicon solar cells lacking chamfered cornersarranged in line with long sides of the silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

arranging at least some of the rectangular silicon solar cellscomprising chamfered corners to form a second plurality of super cellseach of which comprises only rectangular silicon solar cells comprisingchamfered corners arranged in line with long sides of the silicon solarcells overlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series; and

arranging the super cells in parallel rows of super cells ofsubstantially equal length to form a front surface of the solar module,with each row comprising only super cells from the first plurality ofsuper cells or only super cells from the second plurality of supercells.

27. The solar module of clause 26, wherein two of the rows of supercells adjacent to parallel opposite edges of the solar module compriseonly super cells from the second plurality of super cells, and all otherrows of super cells comprise only super cells from the first pluralityof super cells.

28. The solar module of clause 27, wherein the solar module comprises atotal of six rows of super cells.

29. A super cell comprising:

a plurality of silicon solar cells arranged in line in a first directionwith end portions of adjacent silicon solar cells overlapping andconductively bonded to each other to electrically connect the siliconsolar cells in series; and

an elongated flexible electrical interconnect with its long axisoriented parallel to a second direction perpendicular to the firstdirection, conductively bonded to a front or back surface of an end oneof the silicon solar cells at three or more discrete locations arrangedalong the second direction, running at least the full width of the endsolar cell in the second direction, having a conductor thickness lessthan or equal to about 100 microns measured perpendicularly to the frontor rear surface of the end silicon solar cell, providing a resistance tocurrent flow in the second direction of less than or equal to about0.012 Ohms, and configured to provide flexibility accommodatingdifferential expansion in the second direction between the end siliconsolar cell and the interconnect for a temperature range of about −40° C.to about 85° C.

30. The super cell of clause 29, wherein the flexible electricalinterconnect has a conductor thickness less than or equal to about 30microns measured perpendicularly to the front and rear surfaces of theend silicon solar cell.

31. The super cell of clause 29, wherein the flexible electricalinterconnect extends beyond the super cell in the second direction toprovide for electrical interconnection to at least a second super cellpositioned parallel to and adjacent the super cell in a solar module.

32. The super cell of clause 29, wherein the flexible electricalinterconnect extends beyond the super cell in the first direction toprovide for electrical interconnection to a second super cell positionedparallel to and in line with the super cell in a solar module.

33. A solar module comprising:

a plurality of super cells arranged in two or more parallel rowsspanning a width of the module to form a front surface of the module,each super cell comprising a plurality of silicon solar cells arrangedin line with end portions of adjacent silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

wherein at least an end of a first super cell adjacent an edge of themodule in a first row is electrically connected to an end of a secondsuper cell adjacent the same edge of the module in a second row via aflexible electrical interconnect that is bonded to the front surface ofthe first super cell at a plurality of discrete locations with anelectrically conductive adhesive bonding material, runs parallel to theedge of the module, and at least a portion of which folds around the endof the first super cell and is hidden from view from the front of themodule.

34. The solar module of clause 33, wherein surfaces of the flexibleelectrical interconnect on the front surface of the module are coveredor colored to reduce visible contrast with the super cells.

35. The solar module of clause 33, wherein the two or more parallel rowsof super cells are arranged on a white back sheet to form a frontsurface of the solar module to be illuminated by solar radiation duringoperation of the solar module, the white back sheet comprises paralleldarkened stripes having locations and widths corresponding to locationsand widths of gaps between the parallel rows of super cells, and whiteportions of the back sheets are not visible through the gaps between therows.

36. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells,

applying an electrically conductive adhesive bonding material to the oneor more scribed silicon solar cells at one or more locations adjacent along side of each rectangular region;

separating the silicon solar cells along the scribe lines to provide aplurality of rectangular silicon solar cells each comprising a portionof the electrically conductive adhesive bonding material disposed on itsfront surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

37. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, each solar cell comprising a top surface and an oppositelypositioned bottom surface;

applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells;

applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

38. The method of clause 37, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then laser scribing the one or more scribe lines on each of theone or more silicon solar cells.

39. The method of clause 37, comprising laser scribing the one or morescribe lines on each of the one or more silicon solar cells, thenapplying the electrically conductive adhesive bonding material to theone or more silicon solar cells.

40. A solar module comprising:

a plurality of super cells arranged in two or more parallel rows to forma front surface of the solar module, each super cell comprising aplurality of silicon solar cells arranged in line with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series, eachsuper cell comprising a front surface end contact at one end of thesuper cell and a back surface end contact of opposite polarity at anopposite end of the super cell;

wherein a first row of super cells comprises a first super cell arrangedwith its front surface end contact adjacent and parallel to a first edgeof the solar module, and the solar module comprises a first flexibleelectrical interconnect that is elongated and runs parallel to the firstedge of the solar module, is conductively bonded to the front surfaceend contact of the first super cell, and occupies only a narrow portionof the front surface of the solar module adjacent to the first edge ofthe solar module and no wider than about 1 centimeter measuredperpendicularly to the first edge of the solar module.

41. The solar module of clause 40, wherein a portion of the firstflexible electrical interconnect extends around the end of the firstsuper cell nearest to the first edge of the solar module, and behind thefirst super cell.

42. The solar module of clause 40, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a thicker portionrunning parallel to the first edge of the solar module.

43. The solar module of clause 40, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a coiled ribbonportion running parallel to the first edge of the solar module.

44. The solar module of clause 40, wherein a second row of super cellscomprises a second super cell arranged with its front surface endcontact adjacent to and parallel to the first edge of the solar module,and the front surface end contact of the first super cell iselectrically connected to the front surface end contact of the secondsuper cell via the first flexible electrical interconnect.

45. The solar module of clause 40, wherein the back surface end contactof the first super cell is located adjacent to and parallel to a secondedge of the solar module opposite from the first edge of the solarmodule, comprising a second flexible electrical interconnect that iselongated and runs parallel to the second edge of the solar module, isconductively bonded to the back surface end contact of the first supercell, and lies entirely behind the super cells.

46. The solar module of clause 45, wherein:

a second row of super cells comprises a second super cell arranged withits front surface end contact adjacent to and parallel to the first edgeof the solar module and its back surface end contact located adjacent toand parallel to the second edge of the solar module;

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the second super cell viathe first flexible electrical interconnect; and

the back surface end contact of the first super cell is electricallyconnected to the back surface end contact of the second super cell viathe second flexible electrical interconnect.

47. The solar module of clause 40, comprising:

a second super cell arranged in the first row of super cells in serieswith the first super cell and with its back surface end contact adjacenta second edge of the solar module opposite from the first edge of thesolar module; and

a second flexible electrical interconnect that is elongated and runsparallel to the second edge of the solar module, is conductively bondedto the back surface end contact of the first super cell, and liesentirely behind the super cells.

48. The solar module of clause 47, wherein:

a second row of super cells comprises a third super cell and a fourthsuper cell arranged in series with a front surface end contact of thethird super cell adjacent the first edge of the solar module and theback surface end contact of the fourth super cell adjacent the secondedge of the solar module; and

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the third super cell viathe first flexible electrical interconnect and the back surface endcontact of the second super cell is electrically connected to the backsurface end contact of the fourth super cell via the second flexibleelectrical interconnect.

49. The solar module of clause 40, wherein the super cells are arrangedon a white back sheet that comprises parallel darkened stripes havinglocations and widths corresponding to locations and widths of gapsbetween the parallel rows of super cells, and white portions of the backsheets are not visible through the gaps between the rows.

50. The solar module of clause 40, wherein all portions of the firstflexible electrical interconnect located on the front surface of thesolar module are covered or colored to reduce visible contrast with thesuper cells.

51. The solar module of clause 40, wherein:

-   -   each silicon solar cell comprises:        -   rectangular or substantially rectangular front and back            surfaces with shapes defined by first and second oppositely            positioned parallel long sides and two oppositely positioned            short sides, at least portions of the front surfaces to be            exposed to solar radiation during operation of the string of            solar cells;        -   an electrically conductive front surface metallization            pattern disposed on the front surface and comprising a            plurality of fingers running perpendicular to the long sides            and a plurality of discrete front surface contact pads            positioned in a row adjacent to the first long side, each            front surface contact pad electrically connected to at least            one of the fingers; and        -   an electrically conductive back surface metallization            pattern disposed on the back surface and comprising a            plurality of discrete back surface contact pads positioned            in a row adjacent the second long side; and

within each super cell the silicon solar cells are arranged in line withfirst and second long sides of adjacent silicon solar cells overlappingand with corresponding discrete front surface contact pads and discreteback surface contact pads on adjacent silicon solar cells aligned,overlapping, and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series.

52. The solar module of clause 51, wherein the front surfacemetallization pattern of each silicon solar cell comprises a pluralityof thin conductors electrically interconnecting adjacent discrete frontsurface contact pads, and each thin conductor is thinner than the widthof the discrete contact pads measured perpendicularly to the long sidesof the solar cells.

53. The solar module of clause 51, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete front surface contact pads by features of the front surfacemetallization pattern that form one or more barriers adjacent to thediscrete front surface contact pads.

54. The solar module of clause 51, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete back surface contact pads by features of the back surfacemetallization pattern that form one or more barriers adjacent to thediscrete back surface contact pad.

55. A method of making a solar module, the method comprising:

assembling a plurality of super cells, each super cell comprising aplurality of rectangular silicon solar cells arranged in line with endportions on long sides of adjacent rectangular silicon solar cellsoverlapping in a shingled manner;

curing an electrically conductive bonding material disposed between theoverlapping end portions of adjacent rectangular silicon solar cells byapplying heat and pressure to the super cells, thereby bonding adjacentoverlapping rectangular silicon solar cells to each other andelectrically connecting them in series;

arranging and interconnecting the super cells in a desired solar moduleconfiguration in a stack of layers comprising an encapsulant; and

applying heat and pressure to the stack of layers to form a laminatedstructure.

56. The method of clause 55, comprising curing or partially curing theelectrically conductive bonding material by applying heat and pressureto the super cells prior to applying heat and pressure to the stack oflayers to form the laminated structure, thereby forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

57. The method of clause 56, wherein as each additional rectangularsilicon solar cell is added to a super cell during assembly of the supercell, the electrically conductive adhesive bonding material between thenewly added solar cell and its adjacent overlapping solar cell is curedor partially cured before another rectangular silicon solar cell isadded to the super cell.

58. The method of clause 56, comprising curing or partially curing allof the electrically conductive bonding material in a super cell in thesame step.

59. The method of clause 56, comprising:

partially curing the electrically conductive bonding material byapplying heat and pressure to the super cells prior to applying heat andpressure to the stack of layers to form a laminated structure, therebyforming partially cured super cells as an intermediate product beforeforming the laminated structure; and

completing curing of the electrically conductive bonding material whileapplying heat and pressure to the stack of layers to form the laminatedstructure.

60. The method of clause 55, comprising curing the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form a laminated structure, without forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

61. The method of clause 55, comprising dicing one or more silicon solarcells into rectangular shapes to provide the rectangular silicon solarcells.

62. The method of clause 61, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells before dicing the one or more silicon solar cells to providerectangular silicon solar cells with pre-applied electrically conductiveadhesive bonding material.

63. The method of clause 62, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then using a laser to scribe one or more lines on each of the oneor more silicon solar cells, then cleaving the one or more silicon solarcells along the scribed lines.

64. The method of clause 62, comprising using a laser to scribe one ormore lines on each of the one or more silicon solar cells, then applyingthe electrically conductive adhesive bonding material to the one or moresilicon solar cells, then cleaving the one or more silicon solar cellsalong the scribed lines.

65. The method of clause 62, wherein the electrically conductiveadhesive bonding material is applied to a top surface of each of the oneor more silicon solar cells and not to an oppositely positioned bottomsurface of each of the one or more silicon solar cells, comprisingapplying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along scribe lines.

66. The method of clause 61, comprising applying the electricallyconductive adhesive bonding material to the rectangular silicon solarcells after dicing the one or more silicon solar cells to provide therectangular silicon solar cells.

67. The method of clause 55, wherein the conductive adhesive bondingmaterial has a glass transition temperature of less than or equal toabout 0° C.

1A. A solar module comprising:

a plurality of super cells arranged in two or more parallel rows to forma front surface of the solar module, each super cell comprising aplurality of silicon solar cells arranged in line with end portions ofadjacent silicon solar cells overlapping and conductively bonded to eachother to electrically connect the silicon solar cells in series, eachsuper cell comprising a front surface end contact at one end of thesuper cell and a back surface end contact of opposite polarity at anopposite end of the super cell;

wherein a first row of super cells comprises a first super cell arrangedwith its front surface end contact adjacent and parallel to a first edgeof the solar module, and the solar module comprises a first flexibleelectrical interconnect that is elongated and runs parallel to the firstedge of the solar module, is conductively bonded to the front surfaceend contact of the first super cell, and occupies only a narrow portionof the front surface of the solar module adjacent to the first edge ofthe solar module and no wider than about 1 centimeter measuredperpendicularly to the first edge of the solar module.

2A. The solar module of clause 1A, wherein a portion of the firstflexible electrical interconnect extends around the end of the firstsuper cell nearest to the first edge of the solar module, and behind thefirst super cell.

3A. The solar module of clause 1A, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a thicker portionrunning parallel to the first edge of the solar module.

4A. The solar module of clause 1A, wherein the first flexibleinterconnect comprises a thin ribbon portion conductively bonded to thefront surface end contact of the first super cell and a coiled ribbonportion running parallel to the first edge of the solar module.

5A. The solar module of clause 1A, wherein a second row of super cellscomprises a second super cell arranged with its front surface endcontact adjacent to and parallel to the first edge of the solar module,and the front surface end contact of the first super cell iselectrically connected to the front surface end contact of the secondsuper cell via the first flexible electrical interconnect.

6A. The solar module of clause 1A, wherein the back surface end contactof the first super cell is located adjacent to and parallel to a secondedge of the solar module opposite from the first edge of the solarmodule, comprising a second flexible electrical interconnect that iselongated and runs parallel to the second edge of the solar module, isconductively bonded to the back surface end contact of the first supercell, and lies entirely behind the super cells.

7A. The solar module of clause 6A, wherein:

a second row of super cells comprises a second super cell arranged withits front surface end contact adjacent to and parallel to the first edgeof the solar module and its back surface end contact located adjacent toand parallel to the second edge of the solar module;

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the second super cell viathe first flexible electrical interconnect; and

the back surface end contact of the first super cell is electricallyconnected to the back surface end contact of the second super cell viathe second flexible electrical interconnect.

8A. The solar module of clause 1A, comprising:

a second super cell arranged in the first row of super cells in serieswith the first super cell and with its back surface end contact adjacenta second edge of the solar module opposite from the first edge of thesolar module; and

a second flexible electrical interconnect that is elongated and runsparallel to the second edge of the solar module, is conductively bondedto the back surface end contact of the first super cell, and liesentirely behind the super cells.

9A. The solar module of clause 8A, wherein:

a second row of super cells comprises a third super cell and a fourthsuper cell arranged in series with a front surface end contact of thethird super cell adjacent the first edge of the solar module and theback surface end contact of the fourth super cell adjacent the secondedge of the solar module; and

the front surface end contact of the first super cell is electricallyconnected to the front surface end contact of the third super cell viathe first flexible electrical interconnect and the back surface endcontact of the second super cell is electrically connected to the backsurface end contact of the fourth super cell via the second flexibleelectrical interconnect.

10A. The solar module of clause 1A, wherein away from outer edges of thesolar module there are no electrical interconnections between the supercells that reduce the active area of the front surface of the module.

11A. The solar module of clause 1A wherein at least one pair of supercells is arranged in line in a row with the rear surface contact end ofone of the pair of super cells adjacent to the rear surface contact endof the other of the pair of super cells.

12A. The solar module of clause 1A wherein:

at least one pair of super cells is arranged in line in a row withadjacent ends of the two super cells having end contacts of oppositepolarity;

the adjacent ends of the pair of super cells overlap; and

the super cells in the pair of super cells are electrically connected inseries by a flexible interconnect that is sandwiched between theiroverlapping ends and that does not shade the front surface.

13A. The solar module of clause 1A, wherein the super cells are arrangedon a white backing sheet that comprises parallel darkened stripes havinglocations and widths corresponding to locations and widths of gapsbetween the parallel rows of super cells, and white portions of thebacking sheets are not visible through the gaps between the rows.

14A. The solar module of clause 1A, wherein all portions of the firstflexible electrical interconnect located on the front surface of thesolar module are covered or colored to reduce visible contrast with thesuper cells.

15A. The solar module of clause 1A, wherein:

each silicon solar cell comprises:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side, each front surface contact pad        electrically connected to at least one of the fingers; and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete back surface contact pads positioned in a row adjacent        the second long side; and        within each super cell the silicon solar cells are arranged in        line with first and second long sides of adjacent silicon solar        cells overlapping and with corresponding discrete front surface        contact pads and discrete back surface contact pads on adjacent        silicon solar cells aligned, overlapping, and conductively        bonded to each other with a conductive adhesive bonding material        to electrically connect the silicon solar cells in series.

16A. The solar module of clause 15A, wherein the front surfacemetallization pattern of each silicon solar cell comprises a pluralityof thin conductors electrically interconnecting adjacent discrete frontsurface contact pads, and each thin conductor is thinner than the widthof the discrete contact pads measured perpendicularly to the long sidesof the solar cells.

17A. The solar module of clause 15A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete front surface contact pads by features of the front surfacemetallization pattern that form barriers around each discrete frontsurface contact pad.

18A. The solar module of clause 15A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete back surface contact pads by features of the back surfacemetallization pattern that form barriers around each discrete backsurface contact pad.

19A. The solar module of clause 15A, wherein the discrete back surfacecontact pads are discrete silver back surface contact pads, and exceptfor the discrete silver back surface contact pads the back surfacemetallization pattern of each silicon solar cell does not comprise asilver contact at any location that underlies a portion of the frontsurface of the solar cell that is not overlapped by an adjacent siliconsolar cell.

20A. A solar module comprising:

a plurality of super cells, each super cell comprising a plurality ofsilicon solar cells arranged in line with end portions of adjacentsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the silicon solar cells in series;

wherein each silicon solar cell comprises:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side,

each front surface contact pad electrically connected to at least one ofthe fingers; and

-   -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete back surface contact pads positioned in a row adjacent        the second long side;

wherein within each super cell the silicon solar cells are arranged inline with first and second long sides of adjacent silicon solar cellsoverlapping and with corresponding discrete front surface contact padsand discrete back surface contact pads on adjacent silicon solar cellsaligned, overlapping, and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the super cells are arranged in a single row or in two or moreparallel rows substantially spanning a length or width of the solarmodule to form a front surface of the solar module to be illuminated bysolar radiation during operation of the solar module.

21A. The solar module of clause 20A, wherein the discrete back surfacecontact pads are discrete silver back surface contact pads, and exceptfor the discrete silver back surface contact pads the back surfacemetallization pattern of each silicon solar cell does not comprise asilver contact at any location that underlies a portion of the frontsurface of the solar cell that is not overlapped by an adjacent siliconsolar cell.

22A. The solar module of clause 20A, wherein the front surfacemetallization pattern of each silicon solar cell comprises a pluralityof thin conductors electrically interconnecting adjacent discrete frontsurface contact pads, and each thin conductor is thinner than the widthof the discrete contact pads measured perpendicularly to the long sidesof the solar cells.

23A. The solar module of clause 20A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete front surface contact pads by features of the front surfacemetallization pattern that form barriers around each discrete frontsurface contact pad.

24A. The solar module of clause 20A, wherein the conductive adhesivebonding material is substantially confined to the locations of thediscrete back surface contact pads by features of the back surfacemetallization pattern that form barriers around each discrete backsurface contact pad.

25A. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising a plurality of        fingers running perpendicular to the long sides and a plurality        of discrete front surface contact pads positioned in a row        adjacent to the first long side, each front surface contact pad        electrically connected to at least one of the fingers; and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising a plurality of        discrete silver back surface contact pads positioned in a row        adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withcorresponding discrete front surface contact pads and discrete backsurface contact pads on adjacent silicon solar cells aligned,overlapping, and conductively bonded to each other with a conductiveadhesive bonding material to electrically connect the silicon solarcells in series.

26A. The solar module of clause 25A, wherein the discrete back surfacecontact pads are discrete silver back surface contact pads, and exceptfor the discrete silver back surface contact pads the back surfacemetallization pattern of each silicon solar cell does not comprise asilver contact at any location that underlies a portion of the frontsurface of the solar cell that is not overlapped by an adjacent siliconsolar cell.

27A. The string of solar cells of clause 25A, wherein the front surfacemetallization pattern comprises a plurality of thin conductorselectrically interconnecting adjacent discrete front surface contactpads, and each thin conductor is thinner than the width of the discretecontact pads measured perpendicularly to the long sides of the solarcells.

28A. The string of solar cells of clause 25A, wherein the conductiveadhesive bonding material is substantially confined to the locations ofthe discrete front surface contact pads by features of the front surfacemetallization pattern that form barriers around each discrete frontsurface contact pad.

29A. The string of solar cells of clause 25A, wherein the conductiveadhesive bonding material is substantially confined to the locations ofthe discrete back surface contact pads by features of the back surfacemetallization pattern that form barriers around each discrete backsurface contact pad.

30A. The string of solar cells of clause 25A, wherein the conductiveadhesive bonding material has a glass transition less than or equal toabout 0° C.

31A. A method of making a solar module, the method comprising:

assembling a plurality of super cells, each super cell comprising aplurality of rectangular silicon solar cells arranged in line with endportions on long sides of adjacent rectangular silicon solar cellsoverlapping in a shingled manner;

curing an electrically conductive bonding material disposed between theoverlapping end portions of adjacent rectangular silicon solar cells byapplying heat and pressure to the super cells, thereby bonding adjacentoverlapping rectangular silicon solar cells to each other andelectrically connecting them in series;

arranging and interconnecting the super cells in a desired solar moduleconfiguration in a stack of layers comprising an encapsulant; and

applying heat and pressure to the stack of layers to form a laminatedstructure.

32A. The method of clause 31A, comprising curing or partially curing theelectrically conductive bonding material by applying heat and pressureto the super cells prior to applying heat and pressure to the stack oflayers to form the laminated structure, thereby forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

33A. The method of clause 32A, wherein as each additional rectangularsilicon solar cell is added to a super cell during assembly of the supercell, the electrically conductive adhesive bonding material between thenewly added solar cell and its adjacent overlapping solar cell is curedor partially cured before another rectangular silicon solar cell isadded to the super cell.

34A. The method of clause 32A, comprising curing or partially curing allof the electrically conductive bonding material in a super cell in thesame step.

35A. The method of clause 32A, comprising:

partially curing the electrically conductive bonding material byapplying heat and pressure to the super cells prior to applying heat andpressure to the stack of layers to form a laminated structure, therebyforming partially cured super cells as an intermediate product beforeforming the laminated structure; and

completing curing of the electrically conductive bonding material whileapplying heat and pressure to the stack of layers to form the laminatedstructure.

36A. The method of clause 31A, comprising curing the electricallyconductive bonding material while applying heat and pressure to thestack of layers to form a laminated structure, without forming cured orpartially cured super cells as an intermediate product before formingthe laminated structure.

37A. The method of clause 31A, comprising dicing one or more siliconsolar cells into rectangular shapes to provide the rectangular siliconsolar cells.

38A. The method of clause 37A, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells before dicing the one or more silicon solar cells to providerectangular silicon solar cells with pre-applied electrically conductiveadhesive bonding material.

39A. The method of clause 38A, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then using a laser to scribe one or more lines on each of the oneor more silicon solar cells, then cleaving the one or more silicon solarcells along the scribed lines.

40A. The method of clause 38A, comprising using a laser to scribe one ormore lines on each of the one or more silicon solar cells, then applyingthe electrically conductive adhesive bonding material to the one or moresilicon solar cells, then cleaving the one or more silicon solar cellsalong the scribed lines.

41A. The method of clause 38A, wherein the electrically conductiveadhesive bonding material is applied to a top surface of each of the oneor more silicon solar cells and not to an oppositely positioned bottomsurface of each of the one or more silicon solar cells, comprisingapplying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along scribe lines.

42A. The method of clause 37A, comprising applying the electricallyconductive adhesive bonding material to the rectangular silicon solarcells after dicing the one or more silicon solar cells to provide therectangular silicon solar cells.

43A. The method of clause 31A, wherein the conductive adhesive bondingmaterial has a glass transition temperature of less than or equal toabout 0° C.

44A. A method of making a super cell, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, applying an electrically conductive adhesive bondingmaterial to the one or more scribed silicon solar cells at one or morelocations adjacent a long side of each rectangular region;

separating the silicon solar cells along the scribe lines to provide aplurality of rectangular silicon solar cells each comprising a portionof the electrically conductive adhesive bonding material disposed on itsfront surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

45A. A method of making a super cell, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, each solar cell comprising a top surface and an oppositelypositioned bottom surface;

applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells;

applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

46A. A method of making a super cell, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis; and

arranging the rectangular silicon solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein the plurality of rectangular silicon solar cells comprises atleast one rectangular solar cell having two chamfered comerscorresponding to comers or to portions of comers of the pseudo squarewafer, and one or more rectangular silicon solar cells each lackingchamfered comers; and

wherein the spacing between parallel lines along which the pseudo squarewafer is diced is selected to compensate for the chamfered comers bymaking the width perpendicular to the long axis of the rectangularsilicon solar cells that comprise chamfered comers greater than thewidth perpendicular to the long axis of the rectangular silicon solarcells that lack chamfered comers, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

47A. A super cell comprising:

a plurality of silicon solar cells arranged in line with end portions ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein at least one of the silicon solar cells has chamfered comersthat correspond to comers or portions of comers of a pseudo squaresilicon wafer from which it was diced, at least one of the silicon solarcells lacks chamfered comers, and each of the silicon solar cells has afront surface of substantially the same area exposed to light duringoperation of the string of solar cells.

48A. A method of making two or more super cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered comers;

removing the chamfered comers from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered comers;

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength; and

arranging the third plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the thirdplurality of rectangular silicon solar cells in series to form a solarcell string having a width equal to the second length.

49A. A method of making two or more super cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered comers;

arranging the first plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the firstplurality of rectangular silicon solar cells in series; and

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries.

50A. A solar module comprising:

a series connected string of N≧than 25 rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts, the solar cells grouped into one or more supercells each of which comprises two or more of the solar cells arranged inline with long sides of adjacent solar cells overlapping andconductively bonded to each other with an electrically and thermallyconductive adhesive;

wherein no single solar cell or group of <N solar cells in the string ofsolar cells is individually electrically connected in parallel with abypass diode.

51A. The solar module of clause 50A, wherein N is greater than or equalto 30.

52A. The solar module of clause 50A, wherein N is greater than or equalto 50.

53A. The solar module of clause 50A, wherein N is greater than or equalto 100.

54A. The solar module of clause 50A, wherein the adhesive forms bondsbetween adjacent solar cells having a thickness perpendicular to thesolar cells less than or equal to about 0.1 mm and a thermalconductivity perpendicular to the solar cells greater than or equal toabout 1.5 w/m/k.

55A. The solar module of clause 50A, wherein the N solar cells aregrouped into a single super cell.

56A. The solar module of clause 50A, wherein the solar cells are siliconsolar cells.

57A. A solar module comprising:

a super cell substantially spanning a full length or width of the solarmodule parallel to an edge of the solar module, the super cellcomprising a series connected string of N rectangular or substantiallyrectangular solar cells having on average a breakdown voltage greaterthan about 10 volts arranged in line with long sides of adjacent solarcells overlapping and conductively bonded to each other with anelectrically and thermally conductive adhesive;

wherein no single solar cell or group of <N solar cells in the supercell is individually electrically connected in parallel with a bypassdiode.

58A. The solar module of clause 57A, wherein N>24.

59A. The solar module of clause 57A, wherein the super cell has a lengthin the direction of current flow of at least about 500 mm.

60A. A super cell comprising:

-   -   a plurality of silicon solar cells each comprising:        -   rectangular or substantially rectangular front and back            surfaces with shapes defined by first and second oppositely            positioned parallel long sides and two oppositely positioned            short sides, at least portions of the front surfaces to be            exposed to solar radiation during operation of the string of            solar cells;        -   an electrically conductive front surface metallization            pattern disposed on the front surface and comprising at            least one front surface contact pad positioned adjacent to            the first long side; and        -   an electrically conductive back surface metallization            pattern disposed on the back surface and comprising at least            one back surface contact pad positioned adjacent the second            long side;    -   wherein the silicon solar cells are arranged in line with first        and second long sides of adjacent silicon solar cells        overlapping and with front surface and back surface contact pads        on adjacent silicon solar cells overlapping and conductively        bonded to each other with a conductive adhesive bonding material        to electrically connect the silicon solar cells in series; and

wherein the front surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one front surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

61A. The super cell of clause 60A, wherein for each pair of adjacent andoverlapping silicon solar cells, the barrier on the front surface of oneof the silicon solar cells is overlapped and hidden by a portion of theother silicon solar cell, thereby substantially confining the conductiveadhesive bonding material to overlapped regions of the front surface ofthe silicon solar cell prior to curing of the conductive adhesivebonding material during manufacturing of the super cell.

62A. The super cell of clause 60A, wherein the barrier comprises acontinuous conductive line running parallel to and for substantially thefull length of the first long side, with the at least one front surfacecontact pads located between the continuous conductive line and thefirst long side of the solar cell.

63A. The super cell of clause 62A, wherein the front surfacemetallization pattern comprises fingers electrically connected to the atleast one front surface contact pads and running perpendicularly to thefirst long side, and the continuous conductive line electricallyinterconnects the fingers to provide multiple conductive paths from eachfinger to the at least one front surface contact pads.

64A. The super cell of clause 60A, wherein the front surfacemetallization pattern comprises a plurality of discrete contact padsarranged in a row adjacent to and parallel to the first long side, andthe barrier comprises a plurality of features forming separate barriersfor each discrete contact pad that substantially confine the conductiveadhesive bonding material to the discrete contact pads prior to curingof the conductive adhesive bonding material during manufacturing of thesuper cell.

65A. The super cell of clause 64A, wherein the separate barriers abutand are taller than their corresponding discrete contact pads.

66A. A super cell comprising:

a plurality of silicon solar cells each comprising:

-   -   rectangular or substantially rectangular front and back surfaces        with shapes defined by first and second oppositely positioned        parallel long sides and two oppositely positioned short sides,        at least portions of the front surfaces to be exposed to solar        radiation during operation of the string of solar cells;    -   an electrically conductive front surface metallization pattern        disposed on the front surface and comprising at least one front        surface contact pad positioned adjacent to the first long side;        and    -   an electrically conductive back surface metallization pattern        disposed on the back surface and comprising at least one back        surface contact pad positioned adjacent the second long side;

wherein the silicon solar cells are arranged in line with first andsecond long sides of adjacent silicon solar cells overlapping and withfront surface and back surface contact pads on adjacent silicon solarcells overlapping and conductively bonded to each other with aconductive adhesive bonding material to electrically connect the siliconsolar cells in series; and

wherein the back surface metallization pattern of each silicon solarcell comprises a barrier configured to substantially confine theconducive adhesive bonding material to the at least one back surfacecontact pads prior to curing of the conductive adhesive bonding materialduring manufacturing of the super cell.

67A. The super cell of clause 66A, wherein the back surfacemetallization pattern comprises one or more discrete contact padsarranged in a row adjacent to and parallel to the second long side, andthe barrier comprises a plurality of features forming separate barriersfor each discrete contact pad that substantially confine the conductiveadhesive bonding material to the discrete contact pads prior to curingof the conductive adhesive bonding material during manufacturing of thesuper cell.

68A. The super cell of clause 67A, wherein the separate barriers abutand are taller than their corresponding discrete contact pads.

69A. A method of making a string of solar cells, the method comprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a plurality ofrectangular silicon solar cells each having substantially the samelength along its long axis; and

arranging the rectangular silicon solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein the plurality of rectangular silicon solar cells comprises atleast one rectangular solar cell having two chamfered comerscorresponding to comers or to portions of comers of the pseudo squarewafer, and one or more rectangular silicon solar cells each lackingchamfered comers; and

wherein the spacing between parallel lines along which the pseudo squarewafer is diced is selected to compensate for the chamfered comers bymaking the width perpendicular to the long axis of the rectangularsilicon solar cells that comprise chamfered comers greater than thewidth perpendicular to the long axis of the rectangular silicon solarcells that lack chamfered comers, so that each of the plurality ofrectangular silicon solar cells in the string of solar cells has a frontsurface of substantially the same area exposed to light in operation ofthe string of solar cells.

70A. A string of solar cells comprising:

a plurality of silicon solar cells arranged in line with end portions ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series;

wherein at least one of the silicon solar cells has chamfered comersthat correspond to comers or portions of comers of a pseudo squaresilicon wafer from which it was diced, at least one of the silicon solarcells lacks chamfered comers, and each of the silicon solar cells has afront surface of substantially the same area exposed to light duringoperation of the string of solar cells.

71A. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellseach of a first length spanning a full width of the pseudo squaresilicon wafers and lacking chamfered comers;

removing the chamfered comers from each of the first plurality ofrectangular silicon solar cells to form a third plurality of rectangularsilicon solar cells each of a second length shorter than the firstlength and lacking chamfered comers;

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries to form a solar cell string having a width equal to the firstlength; and

arranging the third plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the thirdplurality of rectangular silicon solar cells in series to form a solarcell string having a width equal to the second length.

72A. A method of making two or more strings of solar cells, the methodcomprising:

dicing one or more pseudo square silicon wafers along a plurality oflines parallel to a long edge of each wafer to form a first plurality ofrectangular silicon solar cells comprising chamfered comerscorresponding to comers or portions of comers of the pseudo squaresilicon wafers and a second plurality of rectangular silicon solar cellslacking chamfered comers;

arranging the first plurality of rectangular silicon solar cells in linewith long sides of adjacent rectangular silicon solar cells overlappingand conductively bonded to each other to electrically connect the firstplurality of rectangular silicon solar cells in series; and

arranging the second plurality of rectangular silicon solar cells inline with long sides of adjacent rectangular silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the second plurality of rectangular silicon solar cells inseries.

73A. A method of making a solar module, the method comprising:

dicing each of a plurality of pseudo square silicon wafers along aplurality of lines parallel to a long edge of the wafer to form from theplurality of pseudo square silicon wafers a plurality of rectangularsilicon solar cells comprising chamfered comers corresponding to comersof the pseudo square silicon wafers and a plurality of rectangularsilicon solar cells lacking chamfered comers;

arranging at least some of the rectangular silicon solar cells lackingchamfered comers to form a first plurality of super cells each of whichcomprises only rectangular silicon solar cells lacking chamfered comersarranged in line with long sides of the silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

arranging at least some of the rectangular silicon solar cellscomprising chamfered comers to form a second plurality of super cellseach of which comprises only rectangular silicon solar cells comprisingchamfered comers arranged in line with long sides of the silicon solarcells overlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series; and

arranging the super cells in parallel rows of super cells ofsubstantially equal length to form a front surface of the solar module,with each row comprising only super cells from the first plurality ofsuper cells or only super cells from the second plurality of supercells.

74A. The solar module of clause 73A, wherein two of the rows of supercells adjacent to parallel opposite edges of the solar module compriseonly super cells from the second plurality of super cells, and all otherrows of super cells comprise only super cells from the first pluralityof super cells.

75A. The solar module of clause 74A, wherein the solar module comprisesa total of six rows of super cells.

76A. A super cell comprising:

a plurality of silicon solar cells arranged in line in a first directionwith end portions of adjacent silicon solar cells overlapping andconductively bonded to each other to electrically connect the siliconsolar cells in series; and

an elongated flexible electrical interconnect with its long axisoriented parallel to a second direction perpendicular to the firstdirection, conductively bonded to a front or back surface of an end oneof the silicon solar cells at three or more discrete locations arrangedalong the second direction, running at least the full width of the endsolar cell in the second direction, having a conductor thickness lessthan or equal to about 100 microns measured perpendicularly to the frontor rear surface of the end silicon solar cell, providing a resistance tocurrent flow in the second direction of less than or equal to about0.012 Ohms, and configured to provide flexibility accommodatingdifferential expansion in the second direction between the end siliconsolar cell and the interconnect for a temperature range of about −40° C.to about 85° C.

77A. The super cell of clause 76A, wherein the flexible electricalinterconnect has a conductor thickness less than or equal to about 30microns measured perpendicularly to the front and rear surfaces of theend silicon solar cell.

78A. The super cell of clause 76A, wherein the flexible electricalinterconnect extends beyond the super cell in the second direction toprovide for electrical interconnection to at least a second super cellpositioned parallel to and adjacent the super cell in a solar module.

79A. The super cell of clause 76A, wherein the flexible electricalinterconnect extends beyond the super cell in the first direction toprovide for electrical interconnection to a second super cell positionedparallel to and in line with the super cell in a solar module.

80A. A solar module comprising:

a plurality of super cells arranged in two or more parallel rowsspanning a width of the module to form a front surface of the module,each super cell comprising a plurality of silicon solar cells arrangedin line with end portions of adjacent silicon solar cells overlappingand conductively bonded to each other to electrically connect thesilicon solar cells in series;

wherein at least an end of a first super cell adjacent an edge of themodule in a first row is electrically connected to an end of a secondsuper cell adjacent the same edge of the module in a second row via aflexible electrical interconnect that is bonded to the front surface ofthe first super cell at a plurality of discrete locations with anelectrically conductive adhesive bonding material, runs parallel to theedge of the module, and at least a portion of which folds around the endof the first super cell and is hidden from view from the front of themodule.

81A. The solar module of clause 80A, wherein surfaces of the flexibleelectrical interconnect on the front surface of the module are coveredor colored to reduce visible contrast with the super cells.

82A. The solar module of clause 80A, wherein the two or more parallelrows of super cells are arranged on a white backing sheet to form afront surface of the solar module to be illuminated by solar radiationduring operation of the solar module, the white backing sheet comprisesparallel darkened stripes having locations and widths corresponding tolocations and widths of gaps between the parallel rows of super cells,and white portions of the backing sheets are not visible through thegaps between the rows.

83A. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells,

applying an electrically conductive adhesive bonding material to the oneor more scribed silicon solar cells at one or more locations adjacent along side of each rectangular region;

separating the silicon solar cells along the scribe lines to provide aplurality of rectangular silicon solar cells each comprising a portionof the electrically conductive adhesive bonding material disposed on itsfront surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

84A. A method of making a string of solar cells, the method comprising:

laser scribing one or more scribe lines on each of one or more siliconsolar cells to define a plurality of rectangular regions on the siliconsolar cells, each solar cell comprising a top surface and an oppositelypositioned bottom surface;

applying an electrically conductive adhesive bonding material toportions of the top surfaces of the one or more silicon solar cells;

applying a vacuum between the bottom surfaces of the one or more siliconsolar cells and a curved supporting surface to flex the one or moresilicon solar cells against the curved supporting surface and therebycleave the one or more silicon solar cells along the scribe lines toprovide a plurality of rectangular silicon solar cells each comprising aportion of the electrically conductive adhesive bonding materialdisposed on its front surface adjacent a long side;

arranging the plurality of rectangular silicon solar cells in line withlong sides of adjacent rectangular silicon solar cells overlapping in ashingled manner with a portion of the electrically conductive adhesivebonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular silicon solar cells to each other andelectrically connecting them in series.

85A. The method of clause 84A, comprising applying the electricallyconductive adhesive bonding material to the one or more silicon solarcells, then laser scribing the one or more scribe lines on each of theone or more silicon solar cells.

86A. The method of clause 84A, comprising laser scribing the one or morescribe lines on each of the one or more silicon solar cells, thenapplying the electrically conductive adhesive bonding material to theone or more silicon solar cells.

1B. An apparatus comprising:

a series connected string of at least 25 solar cells connected inparallel with a common bypass diode, each solar cell having a breakdownvoltage greater than about 10 volts and grouped into a super cellcomprising the solar cells arranged with long sides of adjacent solarcells overlapping and conductively bonded with an adhesive.

2B. An apparatus as in clause 1B wherein N is greater than or equal to30.

3B. An apparatus as in clause 1B wherein N is greater than or equal to50.

4B. An apparatus as in clause 1B wherein N is greater than or equal to100.

5B. An apparatus as in clause 1B wherein the adhesive has a thicknessless than or equal to about 0.1 mm, and has a thermal conductivitygreater than or equal to about 1.5 W/m/K.

6B. An apparatus as in clause 1B wherein the N solar cells are groupedinto a single super cell.

7B. An apparatus as in clause 1B wherein the N solar cells are groupedinto a plurality of super cells on a same backing.

8B. An apparatus as in clause 1B wherein the solar cells are siliconsolar cells.

9B. An apparatus as in clause 1B wherein the super cell has a length ina direction of current flow of at least about 500 mm.

10B. An apparatus as in clause 1B wherein the solar cells comprise afeature configured to confine spreading of the adhesive.

11B. An apparatus as in clause 10B wherein the feature comprises araised feature.

12B. An apparatus as in clause 10B wherein the feature comprisesmetallization.

13B. An apparatus as in clause 12B wherein the metallization comprises aline running a full length of the first long side, the apparatus furthercomprising at least one contact pad located between the line and thefirst long side.

14B. An apparatus as in clause 13B wherein:

the metallization further comprises fingers electrically connected tothe at least one contact pad and running perpendicularly to the firstlong side; and

the conductive line interconnects the fingers.

15B. An apparatus as in clause 10B wherein the feature is on a frontside of the solar cell.

16B. An apparatus as in clause 10B wherein the feature is on a back sideof the solar cell.

17B. An apparatus as in clause 10B wherein the feature comprises arecessed feature.

18B. An apparatus as in clause 10B wherein the feature is hidden by anadjacent solar cell of the super cell.

19B. An apparatus as in clause 1B wherein a first solar cell of thesuper cell has chamfered corners and a second solar cell of the supercell lacks chamfered corners, and the first solar cell and the secondsolar cell have a same area exposed to light.

20B. An apparatus as in clause 1B further comprising a flexibleelectrical interconnect having a long axis parallel to a seconddirection perpendicular to the first direction, the flexible electricalinterconnect conductively bonded to a surface of the solar cell andaccommodating thermal expansion of a solar cell in two dimension.

21B. An apparatus as in clause 20B wherein the flexible electricalinterconnect has a thickness less than or equal to about 100 microns toprovide a resistance of less than or equal to about 0.012 Ohms.

22B. An apparatus as in clause 20B wherein the surface comprises a backsurface.

23B. An apparatus as in clause 20B wherein the flexible electricalinterconnect contacts another super cell.

24B. An apparatus as in clause 23B wherein the other super cell is inline with the super cell.

25B. An apparatus as in clause 23B wherein the other super cell isadjacent to the super cell.

26B. An apparatus as in clause 20B wherein a first portion of theinterconnect folds around an edge of the super cell such that aremaining second interconnect portion is on a backside of the supercell.

27B. An apparatus as in clause 20B wherein the flexible electricalinterconnect is electrically connected to a bypass diode.

28B. An apparatus as in clause 1B wherein a plurality of super cells arearranged in two or more parallel rows on a backing sheet to form a solarmodule front surface, wherein the backing sheet is white and comprisesdarkened stripes of location and width corresponding to gaps betweensuper cells.

29B. An apparatus as in clause 1B wherein the super cell comprises atleast one pair of cell strings connected to a power management system.

30B. An apparatus as in clause 1B further comprising a power managementdevice in electrical communication with the super cell and configuredto,

receive a voltage output of the super cell;

based upon the voltage, determine if a solar cell is in reverse bias;and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

31B. An apparatus as in clause 1B wherein the super cell is disposed ona first backing to form a first module having a top conductive ribbon ona first side facing a direction of solar energy, the apparatus furthercomprising:

another super cell disposed on a second backing to form a second modulehaving a bottom ribbon on a second side facing a direction away from thedirection of the solar energy,wherein the second module overlaps and is bonded to a portion of thefirst module including the top ribbon.

32B. An apparatus as in clause 31B wherein the second module is bondedto the first module by adhesive.

33B. An apparatus as in clause 31B wherein the second module is bondedto the first module by a mating arrangement.

34B. An apparatus as in clause 31B further comprising a junction boxoverlapped by the second module.

35B. An apparatus as in clause 34B wherein the second module is bondedto the first module by a mating arrangement.

36B. An apparatus as in clause 35B wherein the mating arrangement isbetween the junction box and another junction box on the second module.

37B. An apparatus as in clause 31B wherein the first backing comprisesglass.

38B. An apparatus as in clause 31B wherein the first backing comprisesother than glass.

39B. An apparatus as in clause 1B wherein the solar cell comprises achamfered portion cut from a larger piece.

40B. An apparatus as in clause 39B wherein the super cell furthercomprises another solar cell having a chamfered portion, wherein a longside of the solar cell is in electrical contact with a long side of theother solar cell that has a similar length.

1C1. A method comprising:

forming a super cell comprising a series connected string of at leastN≧25 solar cells on a same backing, each solar cell having a breakdownvoltage greater than about 10 volts and arranged with long sides ofadjacent solar cells overlapping and conductively bonded with anadhesive; and

connecting each super cell with at most a single bypass diode

2C1. A method as in clause 1C1 wherein N is greater than or equal to 30.

3C1. A method as in clause 1C1 wherein N is greater than or equal to 50.

4C1. A method as in clause 1C1 wherein N is greater than or equal to100.

5C1. A method as in clause 1C1 wherein the adhesive has a thickness lessthan or equal to about 0.1 mm, and has a thermal conductivity greaterthan or equal to about 1.5 w/m/k.

6C1. A method as in clause 1C1 wherein the solar cells are silicon solarcells.

7C1. A method as in clause 1C1 wherein the super cell has a length in adirection of current flow of at least about 500 mm.

8C1. A method as in clause 1C1 wherein a first solar cell of the supercell has chamfered corners and a second solar cell of the super celllacks chamfered corners, and the first solar cell and the second solarcell have a same area exposed to light.

9C1. A method as in clause 1C1 further comprising confining a spreadingof the adhesive utilizing a feature on a solar cell surface.

10C1. A method as in clause 9C1 wherein the feature comprises a raisedfeature.

11C1. A method as in clause 9C1 wherein the feature comprisesmetallization.

12C1. A method as in clause 11C1 wherein the metallization comprises aline running a full length of the first long side, at least one contactpad located between the line and the first long side.

13C1. A method as in clause 12C1 wherein:

the metallization further comprises fingers electrically connected tothe at least one contact pad and running perpendicularly to the firstlong side; and

the conductive line interconnects the fingers.

14C1. A method as in clause 9C1 wherein the feature is on a front sideof the solar cell.

15C1. A method as in clause 9C1 wherein the feature is on a back side ofthe solar cell.

16C1. A method as in clause 9C1 wherein the feature comprises a recessedfeature.

17C1. A method as in clause 9C1 wherein the feature is hidden by anadjacent solar cell of the super cell.

18C1. A method as in clause 1C1 further comprising forming another supercell on the same backing.

19C1. A method as in clause 1C1 further comprising:

conductively bonding to a surface of a solar cell, a flexible electricalinterconnect having a long axis parallel to a second directionperpendicular to the first direction; and

causing the flexible electrical interconnect to accommodate thermalexpansion of the solar cell in two dimensions

20C1. A method as in clause 19C1 wherein the flexible electricalinterconnect has a thickness less than or equal to about 100 microns toprovide a resistance of less than or equal to about 0.012 Ohms.

21C1. A method as in clause 19C1 wherein the surface comprises a backsurface.

22C1. A method as in clause 19C1 further comprising contacting anothersuper cell with the flexible electrical interconnect.

23C1. A method as in clause 22C1 wherein the other super cell is in linewith the super cell.

24C1. A method as in clause 22C1 wherein the other super cell isadjacent to the super cell.

25C1. A method as in clause 19C1 further comprising folding a firstportion of the interconnect around an edge of the super cell such that aremaining second interconnect portion is on a backside of the supercell.

26C1. A method as in clause 19C1 further comprising electricallyconnecting the flexible electrical interconnect to a bypass diode.

27C1. A method as in clause 1C1 further comprising:

arranging a plurality of super cells in two or more parallel rows on thesame backing to form a solar module front surface, wherein the backingsheet is white and comprises darkened stripes of location and widthcorresponding to gaps between super cells.

28C1. A method as in clause 1C1 further comprising connecting at leastone pair of cell strings to a power management system.

29C1. A method as in clause 1C1 further comprising:

electrically connecting a power management device with the super cell;

causing the power management device to receive a voltage output of thesuper cell;

based upon the voltage, causing the power management device to determineif a solar cell is in reverse bias; and

causing the power management device to disconnect the solar cell inreverse bias from a super cell module circuit

30C1. A method as in clause 1C1 wherein the super cell is disposed onthe backing to form a first module having a top conductive ribbon onfirst side facing a direction of solar energy, the method furthercomprising:

disposing another super cell on another backing to form a second modulehaving a bottom ribbon on a second side facing a direction away from thedirection of the solar energy,wherein the second module overlaps and is bonded to a portion of thefirst module including the top ribbon.

31C1. A method as in clause 30C1 wherein the second module is bonded tothe first module by adhesive.

32C1. A method as in clause 30C1 wherein the second module is bonded tothe first module by a mating arrangement.

33C1. A method as in clause 30C1 further comprising overlapping ajunction box with the second module.

34C1. A method as in clause 33C1 wherein the second module is bonded tothe first module by a mating arrangement.

35C1. A method as in clause 34C1 wherein the mating arrangement isbetween the junction box and another junction box on the second module.

36C1. A method as in clause 30C1 wherein the backing comprises glass.

37C1. A method as in clause 30C1 wherein the backing comprises otherthan glass.

38C1. A method as in clause 30C1 further comprising:

electrically connecting a relay switch in series between the firstmodule and the second module;

sensing an output voltage of the first module by a controller; and

activating the relay switch with the controller where the output voltagefalls below a limit.

39C1. A method as in clause 1C1 wherein the solar cell comprises achamfered portion cut from a larger piece.

40C1. A method as in clause 39C1 wherein forming the super cellcomprises placing a long side of the solar cell in electrical contactwith a long side of similar length of another solar cell having achamfered portion.

1C2. An apparatus comprising:

a solar module comprising a front surface including a first seriesconnected string of at least 19 solar cells grouped into a first supercell arranged with long sides of adjacent solar cells overlapping andconductively bonded with an adhesive; and

a ribbon conductor electrically connected to a rear surface contact ofthe first super cell to provide a hidden tap to an electrical component.

2C2. An apparatus as in clause 1C2 wherein the electrical componentcomprises a bypass diode.

3C2. An apparatus as in clause 2C2 wherein the bypass diode is locatedon a rear surface of the solar module.

4C2. An apparatus as in clause 3C2 wherein the bypass diode is locatedoutside of a junction box.

5C2. An apparatus as in clause 4C2 wherein the junction box comprises asingle terminal.

6C2. An apparatus as in clause 3C2 wherein the bypass diode ispositioned near an edge of the solar module.

7C2. An apparatus as in clause 2C2 wherein bypass diode is positioned ina laminate structure.

8C2. An apparatus as in clause 7C2 wherein the first super cell isencapsulated within the laminate structure.

9C2. An apparatus as in clause 2C2 wherein the bypass diode ispositioned around a perimeter of the solar module.

10C2. An apparatus as in clause 1C2 wherein the electrical componentcomprises a module terminal, a junction box, a power management system,a smart switch, a relay, a voltage sensing controller, a centralinverter, a DC/AC micro-inverter, or a DC/DC module power optimizer.

11C2. An apparatus as in clause 1C1 wherein the electrical component islocated on a rear surface of the solar module.

12C2. An apparatus as in clause 1C1 wherein the solar module furthercomprises a second series connected string of at least 19 solar cellsgrouped into a second super cell having a first end electricallyconnected in series to the first super cell.

13C2. An apparatus as in clause 12C2 wherein the second super cell isoverlapping and electrically connected in series to the first super cellwith conductive adhesive.

14C2. An apparatus as in clause 12C2 wherein the rear surface contact islocated away from the first end.

15C2. An apparatus as in clause 12C2 further comprising a flexibleinterconnect between the first end and the first super cell.

16C2. An apparatus as in clause 15C2 wherein the flexible interconnectextends beyond side edges of the first and second super cells toelectrically connect the first and second super cells in parallel withanother super cell.

17C2. An apparatus as in clause 1C2 wherein the adhesive has a thicknessless than or equal to about 0.1 mm, and has a thermal conductivitygreater than or equal to about 1.5 w/m/k.

18C2. An apparatus as in clause 1C2 wherein the solar cells are siliconsolar cells having a breakdown voltage greater than about 10V.

19C2. An apparatus as in clause 1C2 wherein the first super cell has alength in a direction of current flow of at least about 500 mm.

20C2. An apparatus as in clause 1C2 wherein a solar cell of the firstsuper cell comprises a feature configured to confine spreading of theadhesive.

21C2. An apparatus as in clause 20C2 wherein the feature comprises araised feature.

22C2. An apparatus as in clause 21C2 wherein the feature comprisesmetallization.

23C2. An apparatus as in clause 22C2 wherein the metallization comprisesa conductive line running a full length of the first long side, theapparatus further comprising at least one contact pad located betweenthe line and the first long side.

24C2. An apparatus as in clause 23C2 wherein:

the metallization further comprises fingers electrically connected tothe at least one contact pad and running perpendicularly to the firstlong side; and

the conductive line interconnects the fingers.

25C2. An apparatus as in clause 20C2 wherein the feature is on a frontside of the solar cell.

26C2. An apparatus as in clause 20C2 wherein the feature is on a backside of the solar cell.

27C2. An apparatus as in clause 20C2 wherein the feature comprises arecessed feature.

28C2. An apparatus as in clause 20C2 wherein the feature is hidden by anadjacent solar cell of the first super cell.

29C2. An apparatus as in clause 1C2 wherein a solar cell of the firstsuper cell comprises a chamfered portion.

30C2. An apparatus as in clause 29C2 wherein the first super cellfurther comprises another solar cell having a chamfered portion, andwherein a long side of the solar cell is in electrical contact with along side of the other solar cell that has a similar length.

31C2. An apparatus as in clause 29C2 wherein the first super cellfurther comprises another solar cell lacking chamfered corners, and thesolar cell and the other solar cell have a same area exposed to light.

32C2. An apparatus as in clause 1C2 wherein:

the first super cell is arranged with a second super cell in parallelrows on a backing sheet front surface; and

the backing sheet is white and comprises darkened stripes of locationand width corresponding to gaps between the first super cell and thesecond super cell.

33C2. An apparatus as in clause 1C2 wherein the first super cellcomprises at least one pair of cell strings connected to a powermanagement system.

34C2. An apparatus as in clause 1C2 further comprising a powermanagement device in electrical communication with the first super celland configured to,

receive a voltage output of the first super cell;

based upon the voltage, determine if a solar cell of the first supercell is in reverse bias; and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

35C2. An apparatus as in clause 34C2 wherein the power management devicecomprises a relay.

36C2. An apparatus as in clause 1C2 wherein the first super cell isdisposed on a first backing to form the module having a top conductiveribbon on first side facing a direction of solar energy, the apparatusfurther comprising:

another super cell disposed on a second backing to form a differentmodule having a bottom ribbon on a second side facing a direction awayfrom the direction of the solar energy,wherein the different module overlaps and is bonded to a portion of themodule including the top ribbon.

37C2. An apparatus as in clause 36C2 wherein the different module isbonded to the module by adhesive.

38C2. An apparatus as in clause 36C2 wherein the different module isbonded to the module by a mating arrangement.

39C2. An apparatus as in clause 36C2 further comprising a junction boxoverlapped by the different module.

40C2. An apparatus as in clause 39C2 wherein the different module isbonded to the module by a mating arrangement between the junction boxand another junction box on a different solar module.

1C3. An apparatus comprising:

a first super cell disposed on a solar module front surface andcomprising a plurality of solar cells, each having a breakdown voltageof greater than about 10V;

a first ribbon conductor electrically connected with a rear surfacecontact of the first super cell to provide a first hidden tap to anelectrical component;

a second super cell disposed on the solar module front surface andcomprising a plurality of solar cells, each having a breakdown voltageof greater than about 10V; and

a second ribbon conductor electrically connected with a rear surfacecontact of the second super cell to provide a second hidden tap.

2C3. An apparatus as in clause 1C3 wherein the electrical componentcomprises a bypass diode.

3C3. An apparatus as in clause 2C3 wherein the bypass diode is locatedon a solar module rear surface.

4C3. An apparatus as in clause 3C3 wherein the bypass diode is locatedoutside of a junction box.

5C3. An apparatus as in clause 4C3 wherein the junction box comprises asingle terminal.

6C3. An apparatus as in clause 3C3 wherein the bypass diode ispositioned near a solar module edge.

7C3. An apparatus as in clause 2C3 wherein the bypass diode ispositioned in a laminate structure.

8C3. An apparatus as in clause 7C3 wherein the first super cell isencapsulated within the laminate structure.

9C3. An apparatus as in clause 8C3 wherein the bypass diode ispositioned around a solar module perimeter.

10C3. An apparatus as in clause 1C3 wherein the first super cell isconnected in series with the second super cell.

11C3. An apparatus as in clause 10C3 wherein:

the first super cell and the second super cell form a first pair; and

the apparatus further comprises two additional super cells in a secondpair connected in parallel with the first pair.

12C3. An apparatus as in clause 10C3 wherein the second hidden tap isconnected to the electrical component.

13C3. An apparatus as in clause 12C3 wherein the electrical componentcomprises a bypass diode.

14C3. An apparatus as in clause 13C3 wherein the first super cellcomprises not fewer than 19 solar cells.

15C3. An apparatus as in clause 12C3 wherein the electrical componentcomprises a power management system.

16C3. An apparatus as in clause 1C3 wherein the electrical componentcomprises a switch.

17C3. An apparatus as in clause 16C3 further comprising a voltagesensing controller in communication with the switch.

18C3. An apparatus as in clause 16C3 wherein the switch is incommunication with a central inverter.

19C3. An apparatus as in clause 1C3 wherein the electrical componentcomprises a power management device configured to,

receive a voltage output of the first super cell;

based upon the voltage, determine if a solar cell of the first supercell is in reverse bias; and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

20C3. An apparatus as in clause 1 wherein the electrical componentcomprises an inverter.

21C3. An apparatus as in clause 20C3 wherein the inverter comprises aDC/AC micro-inverter.

22C3. An apparatus as in clause 1C3 wherein the electrical componentcomprises a solar module terminal.

23C3. An apparatus as in clause 22C3 wherein the solar module terminalis a single solar module terminal within a junction box.

24C3. An apparatus as in clause 1C3 wherein the electrical component islocated on a solar module rear surface.

25C3. An apparatus as in clause 1C3 wherein the rear surface contact islocated away from an end of the first super cell overlapping the secondsuper cell.

26C3. An apparatus as in clause 1C3 wherein the first super cell has alength in a direction of current flow of at least about 500 mm.

27C3. An apparatus as in clause 1C3 wherein a solar cell of the firstsuper cell comprises a feature configured to confine spreading of theadhesive.

28C3. An apparatus as in clause 27C3 wherein the feature comprises araised feature.

29C3. An apparatus as in clause 28C3 wherein the feature comprisesmetallization.

30C3. An apparatus as in clause 27C3 wherein the feature comprises arecessed feature.

31C3. An apparatus as in clause 27C3 wherein the feature is on a backside of the solar cell.

32C3. An apparatus as in clause 27C3 wherein the feature is hidden by anadjacent solar cell of the first super cell.

33C3. An apparatus as in clause 1C3 wherein a solar cell of the firstsuper cell comprises a chamfered portion.

34C3. An apparatus as in clause 33C3 wherein the first super cellfurther comprises another solar cell having a chamfered portion, andwherein a long side of the solar cell is in electrical contact with along side of the other solar cell that has a similar length.

35C3. An apparatus as in clause 33C3 wherein the first super cellfurther comprises another solar cell lacking chamfered corners, and thesolar cell and the other solar cell have a same area exposed to light.

36C3. An apparatus as in clause 1C3 wherein:

the first super cell is arranged with the second super cell in parallelrows on a backing sheet front surface; and

the backing sheet is white and comprises darkened stripes of locationand width corresponding to gaps between the first super cell and thesecond super cell.

37C3. An apparatus as in clause 1C3 wherein the first super cell isdisposed on a first backing to form a module having a top conductiveribbon on the module front surface facing a direction of solar energy,the apparatus further comprising:

a third super cell disposed on a second backing to form a differentmodule having a bottom ribbon on a second side facing a direction awayfrom the direction of the solar energy,

wherein the different module overlaps and is bonded to a portion of themodule including the top ribbon.

38C3. An apparatus as in clause 37C3 wherein the different module isbonded to the module by adhesive.

39C3. An apparatus as in clause 37C3 further comprising a junction boxoverlapped by the different module.

40C3. An apparatus as in clause 39C3 wherein the different module isbonded to the module by a mating arrangement between the junction boxand another junction box on the different module.

1C4. An apparatus comprising:

a solar module comprising a front surface including a first seriesconnected string of solar cells grouped into a first super cell arrangedwith sides of adjacent solar cells overlapping and conductively bondedwith an adhesive; and

a solar cell surface feature configured to confine the adhesive.

2C4. An apparatus as in clause 1C4 wherein the solar cell surfacefeature comprises a recessed feature.

3C4. An apparatus as in clause 1C4 wherein the solar cell surfacefeature comprises a raised feature.

4C4. An apparatus as in clause 3C4 wherein the raised feature is on afront surface of a solar cell.

5C4. An apparatus as in clause 4C4 wherein the raised feature comprisesa metallization pattern.

6C4. An apparatus as in clause 5C4 wherein the metallization patterncomprises a conductive line running parallel to and substantially alonga long side of the solar cell.

7C4. An apparatus as in clause 6C4 further comprising a contact padbetween the conductive line and the long side.

8C4. An apparatus as in clause 7C4 wherein:

the metallization pattern further comprises a plurality of fingers; and

the conductive line electrically interconnects the fingers to providemultiple conductive paths from each finger to the contact pad.

9C4. An apparatus as in clause 7C4 further comprising a plurality ofdiscrete contact pads arranged in a row adjacent to and parallel to thelong side, the metallization pattern forming a plurality of separatebarriers to confine the adhesive to the discrete contact pads.

10C4. An apparatus as in clause 8C4 wherein the plurality of separatebarriers abut corresponding discrete contact pads.

11C4. An apparatus as in clause 8C4 wherein the plurality of separatebarriers are taller than corresponding discrete contact pads.

12C4. An apparatus as in clause 1C4 wherein the solar cell surfacefeature is hidden by an overlapping side of another solar cell.

13C4. An apparatus as in clause 12C4 wherein the other solar cell ispart of the super cell.

14C4. An apparatus as in clause 12C4 wherein the other solar cell ispart of another super cell.

15C4. An apparatus as in clause 3C4 wherein the raised feature is on aback surface of a solar cell.

16C4. An apparatus as in clause 15C4 wherein the raised featurecomprises a metallization pattern.

17C4. An apparatus as in clause 16C4 wherein the metallization patternforms a plurality of separate barriers to confine the adhesive to aplurality of discrete contact pads located on a front surface of anothersolar cell overlapped by the solar cell.

18C4. An apparatus as in clause 17C4 wherein the plurality of separatebarriers abut corresponding discrete contact pads.

19C4. An apparatus as in clause 17C4 wherein the plurality of separatebarriers are taller than corresponding discrete contact pads.

20C4. An apparatus as in clause 1C1 wherein each solar cell of the supercell has a breakdown voltage of 10V or greater.

21C4. An apparatus as in clause 1C1 wherein the super cell has a lengthin a direction of current flow of at least about 500 mm.

22C4. An apparatus as in clause 1C1 wherein a solar cell of the supercell comprises a chamfered portion.

23C4. An apparatus as in clause 22C4 wherein the super cell furthercomprises another solar cell having a chamfered portion, and wherein along side of the solar cell is in electrical contact with a long side ofthe other solar cell that has a similar length.

24C4. An apparatus as in clause 22C4 wherein the super cell furthercomprises another solar cell lacking chamfered corners, and the solarcell and the other solar cell have a same area exposed to light.

25C4. An apparatus as in clause 1C4 wherein the super cell is arrangedwith a second super cell on a first backing sheet front surface to forma first module.

26C4. An apparatus as in clause 25C4 wherein the backing sheet is whiteand comprises darkened stripes of location and width corresponding togaps between the super cell and the second super cell.

27C4. An apparatus as in clause 25C4 wherein the first module has a topconductive ribbon on a first module front surface facing a direction ofsolar energy, the apparatus further comprising:

a third super cell disposed on a second backing to form a second modulehaving a bottom ribbon on a second module side facing away from thesolar energy, andwherein the second module overlaps and is bonded to a portion of thefirst module including the top ribbon.

28C4. An apparatus as in clause 27C4 wherein the second module is bondedto the first module by adhesive.

29C4. An apparatus as in clause 27C4 further comprising a junction boxoverlapped by the second module.

30C4. An apparatus as in clause 29C4 wherein the second module is bondedto the first module by ca mating arrangement between the junction boxand another junction box on the second module.

31C4. An apparatus as in clause 29C4 wherein the junction box houses asingle module terminal.

32C4. An apparatus as in clause 27C4 further comprising a switch betweenthe first module and the second module.

33C4. An apparatus as in clause 32C4 further comprising a voltagesensing controller in communication with the switch.

34C4. An apparatus as in clause 27C4 wherein the super cell comprisesnot fewer than nineteen solar cells individually electrically connectedin parallel with a single bypass diode.

35C4. An apparatus as in clause 34C4 wherein the single bypass diode ispositioned near a first module edge.

36C4. An apparatus as in clause 34C4 wherein the single bypass diode ispositioned in a laminate structure.

37C4. An apparatus as in clause 36C4 wherein the super cell isencapsulated within the laminate structure.

38C4. An apparatus as in clause 34C4 wherein the single bypass diode ispositioned around a first module perimeter.

39C4. An apparatus as in clause 25C4 wherein the super cell and thesecond super cell comprise a pair individually connected to a powermanagement device.

40C4. An apparatus as in clause 25C4 further comprising a powermanagement device configured to,

receive a voltage output of the super cell;

based upon the voltage, determine if a solar cell of the super cell isin reverse bias; and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

1C5. An apparatus comprising:

a solar module comprising a front surface including a first seriesconnected string of silicon solar cells grouped into a first super cellcomprising a first silicon solar cell having chamfered corners andarranged with a side overlapping and conductively bonded with anadhesive to a second silicon solar cell.

2C5. An apparatus as in clause 1C5 wherein the second silicon solar celllacks chamfered corners, each silicon solar cell of the first super cellhaving substantially a same front surface area exposed to light.

3C5. An apparatus as in clause 2C5 wherein:

the first silicon solar cell and the second silicon solar cell have asame length; and

a width of the first silicon solar cell is greater than a width of thesecond silicon solar cell.

4C5. An apparatus as in clause 3C5 wherein the length reproduces a shapeof a pseudo-square wafer.

5C5. An apparatus as in clause 3C5 wherein the length is 156 mm.

6C5. An apparatus as in clause 3C5 wherein the length is 125 mm.

7C5. An apparatus as in clause 3C5 wherein an aspect ratio between thewidth and the length of the first solar cell is between about 1:2 toabout 1:20.

8C5. An apparatus as in clause 3C5 wherein the first silicon solar celloverlaps the second silicon solar cell by between about 1 mm to about 5mm.

9C5. An apparatus as in clause 3C5 wherein the first super cellcomprises at least nineteen silicon solar cells each having a breakdownvoltage greater than about 10 volts.

10C5. An apparatus as in clause 3C5 wherein the first super cell has alength in a direction of current flow of at least about 500 mm.

11C5. An apparatus as in clause 3C5 wherein:

the first super cell is connected in parallel with a second super cellon the front surface; and

the front surface comprises a white backing featuring darkened stripesof location and width corresponding to gaps between the first super celland the second super cell.

12C5. An apparatus as in clause 1C5 wherein the second silicon solarcell includes chamfered corners.

13C5. An apparatus as in clause 12C5 wherein a long side of the firstsilicon solar cell overlaps a long side of the second silicon solarcell.

14C5. An apparatus as in clause 12C5 wherein a long side of the firstsilicon solar cell overlaps a short side of the second silicon solarcell.

15C5. An apparatus as in clause 1C5 wherein the front surface comprises:

a first row comprising the first super cell consisting of solar cellswith chamfered corners; and

a second row comprising a second series connected string of siliconsolar cells grouped into a second super cell connected in parallel withthe first super cell and consisting of solar cells lacking chamferedcorners, a length of the second row substantially a same as a length ofthe first row.

16C5. An apparatus as in clause 15C5 wherein the first row is adjacentto a module edge and the second row is not adjacent to the module edge.

17C5. An apparatus as in clause 15C5 wherein the first super cellcomprises at least nineteen solar cells each having a breakdown voltagegreater than about 10 volts, and the first super cell has a length in adirection of current flow of at least about 500 mm.

18C5. An apparatus as in clause 15C5 wherein the front surface comprisesa white backing featuring darkened stripes of location and widthcorresponding to gaps between the first super cell and the second supercell.

19C5. An apparatus as in clause 1C5 further comprising a metallizationpattern on a front side of the second solar cell.

20C5. An apparatus as in clause 19C5 wherein the metallization patterncomprises a tapered portion extending around a chamfered corner.

21C5. An apparatus as in clause 19C5 wherein the metallization patterncomprises a raised feature to confine spreading of the adhesive.

22C5. An apparatus as in clause 19C5 wherein the metallization patterncomprises:

a plurality of discrete contact pads;

fingers electrically connected to the a plurality of discrete contactpads; and

a conductive line interconnecting the fingers.

23C5. An apparatus as in clause 22C5 wherein the metallization patternforms a plurality of separate barriers to confine the adhesive to thediscrete contact pads.

24C5. An apparatus as in clause 23C5 wherein the plurality of separatebarriers abut and are taller than corresponding discrete contact pads.

25C5. An apparatus as in clause 1C5 further comprising a flexibleelectrical interconnect conductively bonded to a surface of the firstsolar cell and accommodating thermal expansion of the first solar cellin two dimensions.

26C5. An apparatus as in clause 25C5 wherein a first portion of theinterconnect folds around an edge of the first super cell such that aremaining second interconnect portion is on a backside of the firstsuper cell.

27C5. An apparatus as in clause 1C5 wherein the module has a topconductive ribbon on the front surface facing a direction of solarenergy, the apparatus further comprising:

another module having a second super cell disposed on a front surface, abottom ribbon on the other module facing away from the solar energy, andwherein the second module overlaps and is bonded to a portion of thefirst module including the top ribbon.

28C5. An apparatus as in clause 27C5 wherein the other module is bondedto the module by adhesive.

29C5. An apparatus as in clause 27C5 further comprising a junction boxoverlapped by the other module.

30C5. An apparatus as in clause 29C5 wherein the other module is bondedto the module by a mating arrangement between the junction box andanother junction box on the other module.

31C5. An apparatus as in clause 29C5 wherein the junction box houses asingle module terminal.

32C5. An apparatus as in clause 27C5 further comprising a switch betweenthe module and the other module.

33C5. An apparatus as in clause 32C5 further comprising a voltagesensing controller in communication with the switch.

34C5. An apparatus as in clause 27C5 wherein the first super cellcomprises not fewer than nineteen solar cells electrically connectedwith a single bypass diode.

35C5. An apparatus as in clause 34C5 wherein the single bypass diode ispositioned near a first module edge.

36C5. An apparatus as in clause 34C5 wherein the single bypass diode ispositioned in a laminate structure.

37C5. An apparatus as in clause 36C5 wherein the super cell isencapsulated within the laminate structure.

38C5. An apparatus as in clause 34C5 wherein the single bypass diode ispositioned around a first module perimeter.

39C5. An apparatus as in clause 27C5 wherein the first super cell andthe second super cell comprise a pair connected to a power managementdevice.

40C5. An apparatus as in clause 27C5 further comprising a powermanagement device configured to,

receive a voltage output of the first super cell;

based upon the voltage, determine if a solar cell of the first supercell is in reverse bias; and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

1C6. An apparatus comprising:

a solar module comprising a front surface including a first seriesconnected string of silicon solar cells grouped into a first super cellcomprising a first silicon solar cell having chamfered corners andarranged with a side overlapping and conductively bonded with anadhesive to a second silicon solar cell.

2C6. An apparatus as in clause 106 wherein the second silicon solar celllacks chamfered corners, each silicon solar cell of the first super cellhaving substantially a same front surface area exposed to light.

3C6. An apparatus as in clause 2C6 wherein:

the first silicon solar cell and the second silicon solar cell have asame length; and

a width of the first silicon solar cell is greater than a width of thesecond silicon solar cell.

4C6. An apparatus as in clause 3C6 wherein the length reproduces a shapeof a pseudo-square wafer.

5C6. An apparatus as in clause 3C6 wherein the length is 156 mm.

6C6. An apparatus as in clause 3C6 wherein the length is 125 mm.

7C6. An apparatus as in clause 3C6 wherein an aspect ratio between thewidth and the length of the first solar cell is between about 1:2 toabout 1:20.

8C6. An apparatus as in clause 3C6 wherein the first silicon solar celloverlaps the second silicon solar cell by between about 1 mm to about 5mm.

9C6. An apparatus as in clause 3C6 wherein the first super cellcomprises at least nineteen silicon solar cells each having a breakdownvoltage greater than about 10 volts.

10C6. An apparatus as in clause 3C6 wherein the first super cell has alength in a direction of current flow of at least about 500 mm.

11C6. An apparatus as in clause 3C6 wherein:

the first super cell is connected in parallel with a second super cellon the front surface; and

the front surface comprises a white backing featuring darkened stripesof location and width corresponding to gaps between the first super celland the second super cell.

12C6. An apparatus as in clause 106 wherein the second silicon solarcell includes chamfered corners.

13C6. An apparatus as in clause 12C6 wherein a long side of the firstsilicon solar cell overlaps a long side of the second silicon solarcell.

14C6. An apparatus as in clause 12C6 wherein a long side of the firstsilicon solar cell overlaps a short side of the second silicon solarcell.

15C6. An apparatus as in clause 106 wherein the front surface comprises:

a first row comprising the first super cell consisting of solar cellswith chamfered corners; and

a second row comprising a second series connected string of siliconsolar cells grouped into a second super cell connected in parallel withthe first super cell and consisting of solar cells lacking chamferedcorners, a length of the second row substantially a same as a length ofthe first row.

16C6. An apparatus as in clause 15C6 wherein the first row is adjacentto a module edge and the second row is not adjacent to the module edge.

17C6. An apparatus as in clause 15C6 wherein the first super cellcomprises at least nineteen solar cells each having a breakdown voltagegreater than about 10 volts, and the first super cell has a length in adirection of current flow of at least about 500 mm.

18C6. An apparatus as in clause 15C6 wherein the front surface comprisesa white backing featuring darkened stripes of location and widthcorresponding to gaps between the first super cell and the second supercell.

19C6. An apparatus as in clause 106 further comprising a metallizationpattern on a front side of the second solar cell.

20C6. An apparatus as in clause 19C6 wherein the metallization patterncomprises a tapered portion extending around a chamfered corner.

21C6. An apparatus as in clause 19C6 wherein the metallization patterncomprises a raised feature to confine spreading of the adhesive.

22C6. An apparatus as in clause 19C6 wherein the metallization patterncomprises:

a plurality of discrete contact pads;

fingers electrically connected to the a plurality of discrete contactpads; and

a conductive line interconnecting the fingers.

23C6. An apparatus as in clause 22C6 wherein the metallization patternforms a plurality of separate barriers to confine the adhesive to thediscrete contact pads.

24C6. An apparatus as in clause 23C6 wherein the plurality of separatebarriers abut and are taller than corresponding discrete contact pads.

25C6. An apparatus as in clause 106 further comprising a flexibleelectrical interconnect conductively bonded to a surface of the firstsolar cell and accommodating thermal expansion of the first solar cellin two dimensions.

26C6. An apparatus as in clause 25C6 wherein a first portion of theinterconnect folds around an edge of the first super cell such that aremaining second interconnect portion is on a backside of the firstsuper cell.

27C6. An apparatus as in clause 106 wherein the module has a topconductive ribbon on the front surface facing a direction of solarenergy, the apparatus further comprising:

another module having a second super cell disposed on a front surface, abottom ribbon on the other module facing away from the solar energy, andwherein the second module overlaps and is bonded to a portion of thefirst module including the top ribbon.

28C6. An apparatus as in clause 27C6 wherein the other module is bondedto the module by adhesive.

29C6. An apparatus as in clause 27C6 further comprising a junction boxoverlapped by the other module.

30C6. An apparatus as in clause 29C6 wherein the other module is bondedto the module by a mating arrangement between the junction box andanother junction box on the other module.

31C6. An apparatus as in clause 29C6 wherein the junction box houses asingle module terminal.

32C6. An apparatus as in clause 27C6 further comprising a switch betweenthe module and the other module.

33C6. An apparatus as in clause 32C6 further comprising a voltagesensing controller in communication with the switch.

34C6. An apparatus as in clause 27C6 wherein the first super cellcomprises not fewer than nineteen solar cells electrically connectedwith a single bypass diode.

35C6. An apparatus as in clause 34C6 wherein the single bypass diode ispositioned near a first module edge.

36C6. An apparatus as in clause 34C6 wherein the single bypass diode ispositioned in a laminate structure.

37C6. An apparatus as in clause 36C6 wherein the super cell isencapsulated within the laminate structure.

38C6. An apparatus as in clause 34C6 wherein the single bypass diode ispositioned around a first module perimeter.

39C6. An apparatus as in clause 27C6 wherein the first super cell andthe second super cell comprise a pair connected to a power managementdevice.

40C6. An apparatus as in clause 27C6 further comprising a powermanagement device configured to,

receive a voltage output of the first super cell;

based upon the voltage, determine if a solar cell of the first supercell is in reverse bias; and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

1C7. An apparatus comprising:

a solar module comprising a front surface including a first seriesconnected string of at least nineteen solar cells each having abreakdown voltage greater than about 10V, and grouped into a super cellcomprising a first silicon solar cell arranged with an end overlappingand conductively bonded with an adhesive to a second silicon solar cell;and

an interconnect conductively bonded to a solar cell surface.

2C7. An apparatus as in clause 1C7 wherein the solar cell surfacecomprises a back of the first silicon solar cell.

3C7. An apparatus as in clause 2C7 further comprising a ribbon conductorelectrically connecting the super cell to an electrical component.

4C7. An apparatus as in clause 3C7 wherein the ribbon conductor isconductively bonded to the solar cell surface away from the overlappingend.

5C7. An apparatus as in clause 4C7 wherein the electrical component ison a solar module rear surface.

6C7. An apparatus as in clause 4C7 wherein the electrical componentcomprises a junction box.

7C7. An apparatus as in clause 6C7 wherein the junction box is in matingengagement with another junction box on a different module overlapped bythe module.

8C7. An apparatus as in clause 4C7 wherein the electrical componentcomprises a bypass diode.

9C7. An apparatus as in clause 4C7 wherein the electrical componentcomprises a module terminal.

10C7. An apparatus as in clause 4C7 wherein the electrical componentcomprises an inverter.

11C7. An apparatus as in clause 1007 wherein the inverter comprises aDC/AC micro-inverter.

12C7. An apparatus as in clause 11C7 wherein the DC/AC micro-inverter ison a solar module rear surface.

13C7. An apparatus as in clause 4C7 wherein the electrical componentcomprises a power management device.

14C7. An apparatus as in clause 13C7 wherein the power management devicecomprises a switch.

15C7. An apparatus as in clause 14C7 further comprising a voltagesensing controller in communication with the switch.

16C7. An apparatus as in clause 13C7 wherein the power management deviceis configured to,

receive a voltage output of the super cell;

based upon the voltage, determine if a solar cell of the super cell isin reverse bias; and

disconnect the solar cell in reverse bias from a super cell modulecircuit.

17C7. An apparatus as in clause 16C7 wherein the power management deviceis in electrical communication with a central inverter.

18C7. An apparatus as in clause 13C7 wherein the power management devicecomprises a DC/DC module power optimizer.

19C7. An apparatus as in clause 3C7 wherein the interconnect issandwiched between the super cell and another super cell on the frontsurface.

20C7. An apparatus as in clause 3C7 wherein the ribbon conductor isconductively bonded to the interconnect.

21C7. An apparatus as in clause 3C7 wherein the interconnect provides aresistance to current flow of less than or equal to about 0.012 Ohms.

22C7. An apparatus as in clause 3C7 wherein the interconnect isconfigured to accommodate differential expansion between the firstsilicon solar cell and the interconnect for a temperature range ofbetween about −40° C. to about 85° C.

23C7. An apparatus as in clause 3C7 wherein a thickness of theinterconnect is less than or equal to about 100 microns.

24C7. An apparatus as in clause 3C7 wherein a thickness of theinterconnect is less than or equal to about 30 microns.

25C7. An apparatus as in clause 3C7 wherein the super cell has a lengthin a direction of current flow of at least about 500 mm.

26C7. An apparatus as in clause 3C7 further comprising another supercell on the module front surface.

27C7. An apparatus as in clause 26C7 wherein the interconnect connectsthe other super cell in series with the super cell.

28C7. An apparatus as in clause 26C7 wherein the interconnect connectsthe other super cell in parallel with the super cell.

29C7. An apparatus as in clause 26C7 wherein the front surface comprisesa white backing featuring darkened stripes of location and widthcorresponding to gaps between the super cell and the other super cell.

30C7. An apparatus as in clause 3C7 wherein the interconnect comprises apattern.

31C7. An apparatus as in clause 30C7 wherein the pattern comprisesslits, slots, and/or holes.

32C7. An apparatus as in clause 3C7 wherein a portion of theinterconnect is dark.

33C7. An apparatus as in clause 3C7 wherein:

the first silicon solar cell includes chamfered corners;

the second silicon solar cell lacks chamfered corners; and

each silicon solar cell of the super cell has substantially a same frontsurface area exposed to light.

34C7. An apparatus as in clause 3C7 wherein:

the first silicon solar cell includes chamfered corners;

the second silicon solar cell includes chamfered corners; and

the side comprises a long side overlapping a long side of the secondsilicon solar cell.

35C7. An apparatus as in clause 3C7 wherein the interconnect forms abus.

36C7. An apparatus as in clause 3C7 wherein the interconnect isconductively bonded to the solar cell surface at a glued joint.

37C7. An apparatus as in clause 3C7 wherein a first portion of theinterconnect folds around an edge of the super cell such that aremaining second portion is located on a backside of the super cell.

38C7. An apparatus as in clause 3C7 further comprising a metallizationpattern on the front surface and comprising a line running along a longside, the apparatus further comprising at plurality of discrete contactpads located between the line and the long side.

39C7. An apparatus as in clause 38C7 wherein:

the metallization further comprises fingers electrically connected torespective discrete contact pads and running perpendicularly to the longside; and

the conductive line interconnects the fingers.

40C7. An apparatus as in clause 38C7 wherein the metallization patterncomprises a raised feature to confine spreading of the adhesive.

1C8. An apparatus comprising:

a plurality of super cells arranged in rows on a solar module frontsurface, each super cell comprising at least nineteen silicon solarcells having a breakdown voltage of at least 10V arranged in line withend portions of adjacent silicon solar cells overlapping andconductively bonded to electrically connect the silicon solar cells inseries;

wherein an end of a first super cell adjacent to a module edge in afirst row is electrically connected to an end of a second super celladjacent to the module edge in a second row via a flexible electricalinterconnect bonded to the front surface of the first super cell.

2C8. An apparatus as in clause 1C8 wherein a portion of the flexibleelectrical interconnect is covered by a dark film.

3C8. An apparatus as in clause 2C8 wherein the solar module frontsurface comprises a backing sheet exhibiting reduced visual contrastwith the flexible electrical interconnect.

4C98. An apparatus as in clause 1C8 wherein a portion of the flexibleelectrical interconnect is colored.

5C8. An apparatus as in clause 4C8 wherein the solar module frontsurface comprises a backing sheet exhibiting reduced visual contrastwith the flexible electrical interconnect.

6C8. An apparatus as in clause 1C8 wherein the solar module frontsurface comprises a white backing sheet.

7C8. An apparatus as in clause 6C8 further comprising darkened stripescorresponding to gaps between the rows.

8C8. An apparatus as in clause 6C8 wherein an n-type semiconductor layerof the silicon solar cell faces the backing sheet.

9C8. An apparatus as in clause 1C8 wherein:

the solar module front surface comprises a backing sheet; and

the backing sheet, the flexible electrical interconnect, the first supercell, and an encapsulant comprise a laminated structure.

10C8. An apparatus as in clause 9C8 wherein the encapsulant comprises athermoplastic polymer.

11C8. An apparatus as in clause 1008 wherein the thermoplastic polymercomprises a thermoplastic olefin polymer.

12C8. An apparatus as in clause 9C8 further comprising a front glasssheet.

13C8. An apparatus as in clause 12C8 wherein the backing sheet comprisesglass.

14C8. An apparatus as in clause 1C8 wherein the flexible electricalinterconnect is bonded at a plurality of discrete locations.

15C8. An apparatus as in clause 1C8 wherein the flexible electricalinterconnect is bonded with an electrically conductive adhesive bondingmaterial.

16C8. An apparatus as in clause 1C8 further comprising a glued joint.

17C8. An apparatus as in clause 1C8 wherein the flexible electricalinterconnect runs parallel to the module edge.

18C8. An apparatus as in clause 1C8 wherein a portion of the flexibleelectrical interconnect folds around the first super cell and is hidden.

19C8. An apparatus as in clause 1C8 further comprising a ribbonconductor electrically connecting the first super cell to an electricalcomponent.

20C8. An apparatus as in clause 19C8 wherein the ribbon conductor isconductively bonded to the flexible electrical interconnect.

21C8. An apparatus as in clause 19C8 wherein the ribbon conductor isconductively bonded to a solar cell surface away from an overlappingend.

22C8. An apparatus as in clause 19C8 wherein the electrical component ison a solar module rear surface.

23C8. An apparatus as in clause 19C8 wherein the electrical componentcomprises a junction box.

24C8. An apparatus as in clause 23C8 wherein the junction box is inmating engagement with another junction box on another solar modulefront surface.

25C8. An apparatus as in clause 23C8 wherein the junction box comprisesa single-terminal junction box.

26C8. An apparatus as in clause 19C8 wherein the electrical componentcomprises a bypass diode.

27C8. An apparatus as in clause 19C8 wherein the electrical componentcomprises a switch.

28C8. An apparatus as in clause 27C8 further comprising a voltagesensing controller configured to,

receive a voltage output of the first super cell;

based upon the voltage, determine if a solar cell of the first supercell is in reverse bias; and

communicate with the switch to disconnect the solar cell in reverse biasfrom a super cell module circuit.

29C8. An apparatus as in clause 1C8 wherein the first super cell is inseries with the second super cell.

30C8. An apparatus as in clause 1C8 wherein:

a first silicon solar cell of the first super cell includes chamferedcorners;

a second silicon solar cell of the first super cell lacks chamferedcorners; and

each silicon solar cell of the first super cell has substantially a samefront surface area exposed to light.

31C8. An apparatus as in clause 1C8 wherein:

a first silicon solar cell of the first super cell includes chamferedcorners;

a second silicon solar cell of the first super cell includes chamferedcorners; and

a long side of the first silicon solar cell overlaps a long side of thesecond silicon solar cell.

32C8. An apparatus as in clause 1C8 wherein a silicon solar cell of thefirst super cell comprises a strip having a length of about 156 mm.

33C8. An apparatus as in clause 1C8 wherein a silicon solar cell of thefirst super cell comprises a strip having a length of about 125 mm.

34C8. An apparatus as in clause 1C8 wherein a silicon solar cell of thefirst super cell comprises a strip having an aspect ratio between awidth and a length of between about 1:2 to about 1:20.

35C8. An apparatus as in clause 1C8 wherein the overlapping adjacentsilicon solar cells of the first super cell are conductively bonded withadhesive, the apparatus further comprising a feature configured toconfine spreading of the adhesive.

36C8. An apparatus as in clause 35C8 wherein the feature comprises amoat.

37C8. An apparatus as in clause 36C8 wherein the moat is formed by ametallization pattern.

38C8. An apparatus as in clause 37C8 wherein the metallization patterncomprises a line running along a long side of the silicon solar cell,the apparatus further comprising a plurality of discrete contact padslocated between the line and the long side.

39C8. An apparatus as in clause 37C8 wherein the metallization patternis located on a front of a silicon solar cell of the first super cell.

40C8. An apparatus as in clause 37C8 wherein the metallization patternis located on a back of a silicon solar cell of the second super cell.

1C9. An apparatus comprising:

a solar module comprising a front surface including series connectedsilicon solar cells grouped into a first super cell comprising a firstcut strip having a front side metallization pattern along a firstoutside edge overlapped by a second cut strip.

2C9. An apparatus as in clause 1C9 wherein the first cut strip and thesecond cut strip have a length reproducing a shape of a wafer from whichthe first cut strip is divided.

3C9. An apparatus as in clause 2C9 wherein the length is 156 mm.

4C9. An apparatus as in clause 2C9 wherein the length is 125 mm.

5C9. An apparatus as in clause 2C9 wherein an aspect ratio between awidth of the first cut strip and the length is between about 1:2 toabout 1:20.

6C9. An apparatus as in clause 2C9 wherein the first cut strip includesa first chamfered corner.

7C9. An apparatus as in clause 6C9 wherein the first chamfered corner isalong the first outside edge.

8C9. An apparatus as in clause 6C9 wherein the first chamfered corner isnot along the first outside edge.

9C9. An apparatus as in clause 6C9 wherein the second cut strip includesa second chamfered corner.

10C9. An apparatus as in clause 9C9 wherein an overlapping edge of thesecond cut strip includes the second chamfered corner.

11C9. An apparatus as in clause 9C9 wherein an overlapping edge of thesecond cut strip does not include the second chamfered corner.

12C9. An apparatus as in clause 6C9 wherein the length reproduces ashape of a pseudo-square wafer from which the first cut strip isdivided.

13C9. An apparatus as in clause 6C9 wherein a width of the first cutstrip is different from a width of the second cut strip such that thefirst cut strip and the second cut strip have approximately a same area.

14C9. An apparatus as in clause 1C9 wherein the second cut stripoverlaps the first cut strip by between about 1-5 mm.

15C9. An apparatus as in clause 1C9 wherein the front side metallizationpattern comprises a bus bar.

16C9. An apparatus as in clause 15C9 wherein bus bar includes a taperedportion.

17C9. An apparatus as in clause 1C9 wherein the front side metallizationpattern comprises a discrete contact pad.

18C9. An apparatus as in clause 17C9 wherein:

second cut strip is bonded to the first cut strip by adhesive; and

the discrete contact pad further comprises a feature to confine adhesivespreading.

19C9. An apparatus as in clause 18C9 wherein the feature comprises amoat.

20C9. An apparatus as in clause 1C9 wherein the front side metallizationpattern comprises a bypass conductor.

21C9. An apparatus as in clause 1C9 wherein the front side metallizationpattern comprises a finger.

22C9. An apparatus as in clause 1C9 wherein the first cut strip furthercomprises a rear side metallization pattern along a second outside edgeopposite to the first outside edge.

23C9. An apparatus as in clause 22C9 wherein the rear side metallizationpattern comprises a contact pad.

24C9. An apparatus as in clause 22C9 wherein the rear side metallizationpattern comprises a bus bar.

25C9. An apparatus as in clause 1C9 wherein the super cell comprises atleast nineteen silicon cut strips each having a breakdown voltagegreater than about 10 volts.

26C9. An apparatus as in clause 1C9 wherein the super cell is connectedwith another super cell on the module front surface.

27C9. An apparatus as in clause 26C9 wherein the module front surfacecomprises a white backing featuring darkened stripes corresponding togaps between the super cell and the other super cell.

28C9. An apparatus as in clause 26C9 wherein:

the solar module front surface comprises a backing sheet; and

the backing sheet, the interconnect, the super cell, and an encapsulantcomprise a laminated structure.

29C9. An apparatus as in clause 28C9 wherein the encapsulant comprises athermoplastic polymer.

30C9. An apparatus as in clause 29C9 wherein the thermoplastic polymercomprises a thermoplastic olefin polymer.

31C9. An apparatus as in clause 26C9 further comprising an interconnectbetween the super cell and the other super cell.

32C9. An apparatus as in clause 31C9 wherein a portion of theinterconnect is covered by a dark film.

33C9. An apparatus as in clause 31C9 wherein a portion of theinterconnect is colored.

34C9. An apparatus as in clause 31C9 further comprising a ribbonconductor electrically connecting the super cell to an electricalcomponent.

35C9. An apparatus as in clause 34C9 wherein the ribbon conductor isconductively bonded to a rear side of the first cut strip.

36C9. An apparatus as in clause 34C9 wherein the electrical componentcomprises a bypass diode.

37C9. An apparatus as in clause 34C9 wherein the electrical componentcomprises a switch.

38C9. An apparatus as in clause 34C9 wherein the electrical componentcomprises a junction box.

39C9. An apparatus as in clause 38C9 wherein the junction box overlapsand is in mating arrangement with another junction box.

40C9. An apparatus as in clause 26C9 wherein the super cell and theother super cell are connected in series.

1C10. A method comprising:

laser scribing a scribe line on a silicon wafer to define a solar cellregion;

applying an electrically conductive adhesive bonding material to a topsurface of the scribed silicon wafer adjacent to a long side of thesolar cell region; and

separating the silicon wafer along the scribe line to provide a solarcell strip comprising a portion of the electrically conductive adhesivebonding material disposed adjacent to a long side of the solar cellstrip.

2C10. A method as in clause 1C10 further comprising providing thesilicon wafer with a metallization pattern, such that the separatingproduces the solar cell strip having the metallization pattern along thelong side.

3C10. A method as in clause 2C10 wherein the metallization patterncomprises a bus bar or a discrete contact pad.

4C10. A method as in clause 2C10 wherein the providing comprisesprinting the metallization pattern.

5C10. A method as in clause 2C10 wherein the providing compriseselectroplating the metallization pattern.

6C10. A method as in clause 2C10 wherein the metallization patterncomprises a feature configured to confine spreading of the electricallyconductive adhesive bonding material.

7C10. An apparatus as in clause 6C10 wherein the feature comprises amoat.

8C10. A method as in clause 1C10 wherein the applying comprisesprinting.

9C10. A method as in clause 1C10 wherein the applying comprisesdepositing using a mask.

10C10. A method as in clause 1C10 wherein a length of the long side ofthe solar cell strip reproduces a shape of the wafer.

11C10. A method as in clause 1C10 wherein the length is 156 mm or 125mm.

12C10. A method as in clause 10C10 wherein an aspect ratio between awidth of the solar cell strip and the length is between about 1:2 toabout 1:20.

13C10. A method as in clause 1C10 wherein the separating comprises:

applying a vacuum between a bottom surface of the wafer and a curvedsupporting surface to flex the solar cell region against the curvedsupporting surface and thereby cleave the silicon wafer along the scribeline.

14C10. A method as in clause 1C10 further comprising:

arranging a plurality of solar cell strips in line with long sides ofadjacent solar cell strips overlapping and a portion of the electricallyconductive adhesive bonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping solar cell strips to each other and electricallyconnecting them in series.

15C10. A method as in clause 14C10 wherein the curing comprises theapplication of heat.

16C10. A method as in clause 14C10 wherein the curing comprises theapplication of pressure.

17C10. A method as in clause 14C10 wherein the arranging comprisesforming a layered structure.

18C10. A method as in clause 17C10 wherein the curing comprises theapplication of heat and pressure to the layered structure.

19C10. A method as in clause 17C10 wherein the layered structurecomprises an encapsulant.

20C10. A method as in clause 19C10 wherein the encapsulant comprises athermoplastic polymer.

21C10. A method as in clause 20C10 wherein the thermoplastic polymercomprises a thermoplastic olefin polymer.

22C10. A method as in clause 17C10 wherein the layered structurecomprises a backing sheet.

23C10. A method as in clause 22C10 wherein:

the backing sheet is white; and

the layered structure further comprises darkened stripes.

24C10. A method as in clause 14C10 wherein the arranging comprisesarranging at least nineteen solar cell strips in line.

25C10. A method as in clause 24C10 wherein each of the at least nineteensolar cell strips has a breakdown voltage of at least 10V.

26C10. A method as in clause 24C10 further comprising placing the atleast nineteen solar cell strips in communication with only a singlebypass diode.

27C10. A method as in clause 26C10 further comprising forming a ribbonconductor between one of the at least nineteen solar cell strips and thesingle bypass diode.

28C10. A method as in clause 27C10 wherein the single bypass diode islocated in a junction box.

29C10. A method as in clause 28C10 wherein the junction box is on a backside of a solar module, in mating arrangement with another junction boxof a different solar module.

30C10. A method as in clause 14C10 wherein an overlapping cell strip ofthe plurality of solar cell strips, overlaps the solar cell strip bybetween about 1-5 mm.

31C10. A method as in clause 14C10 wherein the solar cell strip includesa first chamfered corner.

32C10. A method as in clause 31C10 wherein a long side of an overlappingsolar cell strip of the plurality of solar cell strips, does not includea second chamfered corner.

33C10. A method as in clause 32C10 wherein a width of the solar cellstrip is greater than a width of the overlapping solar cell strip, suchthat the solar cell strip and the overlapping solar cell strip haveapproximately a same area.

34C10. A method as in clause 31C10 wherein a long side of an overlappingsolar cell strip of the plurality of solar cell strips, includes asecond chamfered corner.

35C10. A method as in clause 34C10 wherein the long side of theoverlapping solar cell strip of the plurality of solar cell strips,overlaps the long side of the cell strip including the first chamferedcorner.

36C10. A method as in clause 34C10 wherein the long side of theoverlapping solar cell strip of the plurality of solar cell strips,overlaps a long side of the cell strip not including the first chamferedcorner.

37C10. A method as in clause 14C10 further comprising connecting theplurality of solar cell strips with another plurality of solar cellstrips utilizing an interconnect.

38C10. A method as in clause 37C10 wherein a portion of the interconnectis covered by a dark film.

39C10. A method as in clause 37C10 wherein a portion of the interconnectis colored.

40C10. A method as in clause 37C10 wherein the plurality of solar cellstrips is connected in series with the other plurality of solar cellstrips.

1C11. A method comprising:

providing a silicon wafer having a length;

scribing a scribe line on the silicon wafer to define a solar cellregion;

applying an electrically conductive adhesive bonding material to asurface of the silicon wafer; and

separating the silicon wafer along the scribe line to provide a solarcell strip comprising a portion of the electrically conductive adhesivebonding material disposed adjacent to a long side of the solar cellstrip.

2C11. A method as in clause 1C11 wherein the scribing comprises laserscribing.

3C11. A method as in clause 2C11 comprising laser scribing the scribeline, and then applying the electrically conductive adhesive bondingmaterial.

4C11. A method as in clause 2C11 comprising the applying theelectrically conductive adhesive bonding material to the wafer, and thenlaser scribing the scribe line.

5C11. A method as in clause 4C11 wherein:

the applying comprises applying uncured electrically conductive adhesivebonding material; and

the laser scribing comprises avoiding curing the uncured conductiveadhesive bonding material with heat from the laser.

6C11. A method as in clause 5C11 wherein the avoiding comprisesselecting a laser power and/or a distance between the scribe line andthe uncured conductive adhesive bonding material.

7C11. A method as in clause 1C11 wherein the applying comprisesprinting.

8C11. A method as in clause 1C11 wherein the applying comprisesdepositing using a mask.

9C11. A method as in clause 1C11 wherein the scribe line and theelectrically conductive adhesive bonding material are on the surface.

10C11. A method as in clause 1C11 wherein the separating comprises:

applying a vacuum between a surface of the wafer and a curved supportingsurface to flex the solar cell region against the curved supportingsurface and thereby cleave the silicon wafer along the scribe line.

11C11. A method as in clause 10C11 wherein the separating comprisesarranging the scribe line at an angle relative to a vacuum manifold.

12C11. A method as in clause 1C11 wherein the separating comprises usinga roller to apply pressure to the wafer.

13C11. A method as in clause 1C11 wherein the providing comprisesproviding the silicon wafer with a metallization pattern, such that theseparating produces the solar cell strip having the metallizationpattern along the long side.

14C11. A method as in clause 13C11 wherein the metallization patterncomprises a bus bar or a discrete contact pad.

15C11. A method as in clause 13C11 wherein the providing comprisesprinting the metallization pattern.

16C11. A method as in clause 13C11 wherein the providing compriseselectroplating the metallization pattern.

17C11. A method as in clause 13C11 wherein the metallization patterncomprises a feature configured to confine spreading of the electricallyconductive adhesive bonding material.

18C11. A method as in clause 1C11 wherein a length of the long side ofthe solar cell strip reproduces a shape of the wafer.

19C11. A method as in clause 18C11 wherein the length is 156 mm or 125mm.

20C11. A method as in clause 18C11 wherein an aspect ratio between awidth of the solar cell strip and the length is between about 1:2 toabout 1:20.

21C11. A method as in clause 1C11 further comprising:

arranging a plurality of solar cell strips in line with long sides ofadjacent solar cell strips overlapping and a portion of the electricallyconductive adhesive bonding material disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping solar cell strips to each other and electricallyconnecting them in series.

22C11. A method as in clause 21C11 wherein:

the arranging comprises forming a layered structure; and

the curing comprises the application of heat and/or pressure to thelayered structure.

23C11. A method as in clause 22C11 wherein the layered structurecomprises a thermoplastic olefin polymer encapsulant.

24C11. A method as in clause 22C11 wherein the layered structurecomprises:

a white backing sheet; and

darkened stripes on the white backing sheet.

25C11. A method as in clause 21C11 wherein:

a plurality of wafers are provided on a template;

the conductive adhesive bonding material is dispensed on the pluralityof wafers; and

the plurality of wafers are cells simultaneously separated into aplurality of solar cell strips with a fixture.

26C11. A method as in clause 25C11 further comprising transporting theplurality of solar cell strips as a group, and wherein the arrangingcomprises arranging the plurality of solar cell strips into a module.

27C11. A method as in clause 21C11 wherein the arranging comprisesarranging at least nineteen solar cell strips having a breakdown voltageof at least 10V in line with only a single bypass diode.

28C11. A method as in clause 27C11 further comprising forming a ribbonconductor between one of the at least nineteen solar cell strips and thesingle bypass diode.

29C11. A method as in clause 28C11 wherein the single bypass diode islocated in a first junction box of a first solar module that is inmating arrangement with a second junction box of a second solar module.

30C11. A method as in clause 27C11 further comprising forming a ribbonconductor between one of the at least nineteen solar cell strips and asmart switch.

31C11. A method as in clause 21C11 wherein an overlapping cell strip ofthe plurality of solar cell strips, overlaps the solar cell strip bybetween about 1-5 mm.

32C11. A method as in clause 21C11 wherein the solar cell strip includesa first chamfered corner.

33C11. A method as in clause 32C11 wherein a long side of an overlappingsolar cell strip of the plurality of solar cell strips, does not includea second chamfered corner.

34C11. A method as in clause 33C11 wherein a width of the solar cellstrip is greater than a width of the overlapping solar cell strip, suchthat the solar cell strip and the overlapping solar cell strip haveapproximately a same area.

35C11. A method as in clause 32C11 wherein a long side of an overlappingsolar cell strip of the plurality of solar cell strips, includes asecond chamfered corner.

36C11. A method as in clause 35C11 wherein the long side of theoverlapping solar cell strip of the plurality of solar cell strips,overlaps the long side of the cell strip including the first chamferedcorner.

37C11. A method as in clause 35C11 wherein the long side of theoverlapping solar cell strip of the plurality of solar cell strips,overlaps a long side of the cell strip not including the first chamferedcorner.

38C11. A method as in clause 21C11 further comprising connecting theplurality of solar cell strips with another plurality of solar cellstrips utilizing an interconnect.

39C11. A method as in clause 38C11 wherein a portion of the interconnectis covered by a dark film or is colored.

40C11. A method as in clause 38C11 wherein the plurality of solar cellstrips is connected in series with the other plurality of solar cellstrips.

1C12. A method comprising:

providing a silicon wafer having a length;

scribing a scribe line on a silicon wafer to define a solar cell region;

separating the silicon wafer along the scribe line to provide a solarcell strip; and

applying an electrically conductive adhesive bonding material disposedadjacent to a long side of the solar cell strip.

2C12. A method as in clause 1C12 wherein the scribing comprises laserscribing.

3C12. A method as in clause 1C12 wherein the applying comprises screenprinting.

4C12. A method as in clause 1C12 wherein the applying comprises ink jetprinting.

5C12. A method as in clause 1C12 wherein the applying comprisesdepositing using a mask.

6C12. A method as in clause 1C12 wherein the separating comprisesapplying a vacuum between a surface of the wafer and a curved surface.

7C12. A method as in clause 6C12 wherein the curved surface comprises avacuum manifold, and the separating comprises orienting the scribe lineat an angle relative to the vacuum manifold.

8C12. A method as in clause 7C12 wherein the angle is perpendicular.

9C12. A method as in clause 7C12 wherein the angle is other thanperpendicular.

10C12. A method as in clause 6C12 wherein the vacuum is applied througha moving belt.

11C12. A method as in clause 1C12 further comprising:

arranging a plurality of solar cell strips in line with long sides ofadjacent solar cell strips overlapping the electrically conductiveadhesive bonding material disposed in between; and

curing the electrically conductive bonding material to bond adjacentoverlapping solar cell strips electrically connected in series.

12C12. A method as in clause 11C12 wherein the arranging comprisesforming a layered structure including an encapsulant, the method furthercomprising laminating the layered structure.

13C12. A method as in clause 12C12 wherein the curing occurs at leastpartially during the laminating

14C12. A method as in clause 12C12 wherein the curing occurs distinctfrom the laminating.

15C12. A method as in clause 12C12 wherein the laminating comprisesapplying a vacuum.

16C12. A method as in clause 15C12 wherein the vacuum is applied to abladder.

17C12. A method as in clause 15C12 wherein the vacuum is applied to abelt.

18C12. A method as in clause 12C12 wherein the encapsulant comprises athermoplastic olefin polymer.

19C12. A method as in clause 12C12 wherein the layered structurecomprises:

a white backing sheet; and

darkened stripes on the white backing sheet.

20C12. A method as in clause 11C12 wherein the providing comprisesproviding the silicon wafer with a metallization pattern, such that theseparating produces the solar cell strip having the metallizationpattern along the long side.

21C12. A method as in clause 20C12 wherein the metallization patterncomprises a bus bar or a discrete contact pad.

22C12. A method as in clause 20C12 wherein the providing comprisesprinting or electroplating the metallization pattern.

23C12. A method as in clause 20C12 wherein the arranging comprisesconfining a spreading of the electrically conductive adhesive bondingmaterial using a feature of the metallization pattern.

24C12. A method as in clause 23C12 wherein the feature is on a frontside of the solar cell strip.

25C12. A method as in clause 23C12 wherein the feature is on a back sideof the solar cell strip.

26C12. A method as in clause 11C12 wherein a length of the long side ofthe solar cell strip reproduces a shape of the wafer.

27C12. A method as in clause 26C12 wherein the length is 156 mm or 125mm.

28C12. A method as in clause 26C12 wherein an aspect ratio between awidth of the solar cell strip and the length is between about 1:2 toabout 1:20.

29C12. A method as in clause 11C12 wherein the arranging comprisesarranging at least nineteen solar cell strips having a breakdown voltageof at least 10V in line as a first super cell with only a single bypassdiode.

30C12. A method as in clause 29C12 further comprising applying theelectrically conductive adhesive bonding material between the firstsuper cell and an interconnect.

31C12. A method as in clause 30C12 wherein the interconnect connects thefirst super cell in parallel with a second super cell.

32C12. A method as in clause 30C12 wherein the interconnect connects thefirst super cell in series with a second super cell.

33C12. A method as in clause 29C12 further comprising forming a ribbonconductor between the first super cell and the single bypass diode.

34C12. A method as in clause 33C12 wherein the single bypass diode islocated in a first junction box of a first solar module that is inmating arrangement with a second junction box of a second solar module.

35C12. A method as in clause 11C12 wherein the solar cell strip includesa first chamfered corner.

36C12. A method as in clause 35C12 wherein a long side of an overlappingsolar cell strip of the plurality of solar cell strips, does not includea second chamfered corner.

37C12. A method as in clause 36C12 wherein a width of the solar cellstrip is greater than a width of the overlapping solar cell strip, suchthat the solar cell strip and the overlapping solar cell strip haveapproximately a same area.

38C12. A method as in clause 35C12 wherein a long side of an overlappingsolar cell strip of the plurality of solar cell strips, includes asecond chamfered corner.

39C12. A method as in clause 38C12 wherein the long side of theoverlapping solar cell strip of the plurality of solar cell strips,overlaps the long side of the cell strip including the first chamferedcorner.

40C12. A method as in clause 38C12 wherein the long side of theoverlapping solar cell strip of the plurality of solar cell strips,overlaps a long side of the cell strip not including the first chamferedcorner.

1C13. An apparatus comprising:

a semiconductor wafer having a first surface including a firstmetallization pattern along a first outside edge, and a secondmetallization pattern along a second outside edge opposite to the firstoutside edge, the semiconductor wafer further comprising a first scribeline between the first metallization pattern and the secondmetallization pattern.

2C13. An apparatus as in clause 1C13 wherein the first metallizationpattern comprises a discrete contact pad.

3C13. An apparatus as in clause 1C13 wherein the first metallizationpattern comprises a first finger pointing away from the first outsideedge toward the second metallization pattern.

4C13. An apparatus as in clause 3C13 wherein the first metallizationpattern further comprises a bus bar running along the first outside edgeand intersecting the first finger.

5C13. An apparatus as in clause 4C13 wherein the second metallizationpattern comprises:

a second finger pointing away from the second outside edge toward thefirst metallization pattern; and

a second bus bar running along the second outside edge and intersectingthe second finger.

6C13. An apparatus as in clause 3C13 further comprising an electricallyconductive adhesive running along the first outside edge and in contactwith the first finger.

7C13. An apparatus as in clause 3C13 wherein the first metallizationpattern further comprises a first bypass conductor.

8C13. An apparatus as in clause 3C13 wherein the first metallizationpattern further comprises a first end conductor.

9C13. An apparatus as in clause 1C13 wherein the first metallizationpattern comprises silver.

10C13. An apparatus as in clause 9C13 wherein the first metallizationpattern comprises silver paste.

11C13. An apparatus as in clause 9C13 wherein the first metallizationpattern comprises discrete contacts.

12C13. An apparatus as in clause 1C13 wherein the first metallizationpattern comprises tin, aluminum, or another conductor less expensivethan silver.

13C13. An apparatus as in clause 1C13 wherein the first metallizationpattern comprises copper.

14C13. An apparatus as in clause 13C13 wherein the first metallizationpattern comprises electroplated copper.

15C13. An apparatus as in clause 13C13 further comprising a passivationscheme to reduce recombination.

16C13. An apparatus as in clause 1C13 further comprising:

a third metallization pattern on the first surface of the semiconductorwafer not proximate to the first outside edge or to the second outsideedge; and

a second scribe line between the third metallization pattern and thesecond metallization pattern, wherein the first scribe line is betweenthe first metallization pattern and the third metallization pattern.

17C13. An apparatus as in clause 16C13 wherein a ratio of a first widthdefined between the first scribe line and the second scribe line dividedby a length of the semiconductor wafer, is between about 1:2 to about1:20.

18C13. An apparatus as in clause 17C13 wherein the length is about 156mm or about 125 mm.

19C13. An apparatus as in clause 17C13 wherein the semiconductor waferincludes chamfered corners.

20C13. An apparatus as in clause 19C13 wherein:

the first scribe line defines with the first outside edge, a firstrectangular region comprising two chamfered corners and the firstmetallization pattern, the first rectangular region having an areacorresponding to a product of the length and a second width greater thanthe first width, minus a combined area of the two chamfered corners; and

the second scribe line defines with the first scribe line, a secondrectangular region not including chamfered corners and including thethird metallization pattern, the second rectangular region having thearea corresponding to a product of the length and the first width.

21C13. An apparatus as in clause 16C13 wherein the third metallizationpattern comprises a finger pointing toward the second metallizationpattern.

22C13. An apparatus as in clause 1C13 further comprising a thirdmetallization pattern on a second surface of the semiconductor waferopposite to the first surface.

23C13. An apparatus as in clause 22C13 wherein the third metallizationpattern comprises a contact pad proximate to a location of the firstscribe line.

24C13. An apparatus as in clause 1C13 wherein the first scribe line isformed by a laser.

25C13. An apparatus as in clause 1C13 wherein the first scribe line isin the first surface.

26C13. An apparatus as in clause 1C13 wherein first metallizationpattern comprises a feature configured to confine spreading of anelectrically conducting adhesive.

27C13. An apparatus as in clause 26C13 wherein the feature comprises araised feature.

28C13. An apparatus as in clause 27C13 wherein the first metallizationpattern comprises a contact pad, and the feature comprises a damabutting and taller than the contact pad.

29C13. An apparatus as in clause 26C13 wherein the feature comprises arecessed feature.

30C13. An apparatus as in clause 29C13 wherein the recessed featurecomprises a moat.

31C13. An apparatus as in clause 26C13 further comprising theelectrically conducting adhesive in contact with the first metallizationpattern.

32C13. An apparatus as in clause 31C13 wherein the electricallyconducting adhesive is printed.

33C13. An apparatus as in clause 1C13 wherein the semiconductor wafercomprises silicon.

34C13. An apparatus as in clause 33C13 wherein the semiconductor wafercomprises crystalline silicon.

35C13. An apparatus as in clause 33C13 wherein the first surface is ofn-type conductivity.

36C13. An apparatus as in clause 33C13 wherein the first surface is ofp-type conductivity.

37C13. An apparatus as in clause 1C13 wherein:

the first metallization pattern is 5 mm or less from the first outsideedge; and

the second metallization pattern is 5 mm or less from the second outsideedge.

38C13. An apparatus as in clause 1C13 wherein the semiconductor waferincludes chamfered corners, and the first metallization patterncomprises a tapered portion extending around a chamfered corner.

39C13. An apparatus as in clause 38C13 wherein the tapered portioncomprises a bus bar.

40C13. An apparatus as in clause 38C13 wherein the tapered portioncomprises a conductor connecting a discrete contact pad.

1C14. A method comprising:

scribing a first scribe line on a wafer; and

separating the wafer along the first scribe line utilizing a vacuum toprovide a solar cell strip.

2C14. A method as in clause 1C14 wherein the scribing comprises laserscribing.

3C14. A method as in clause 2C14 wherein the separating comprisesapplying the vacuum between a surface of the wafer and a curved surface.

4C14. A method as in clause 3C14 wherein the curved surface comprises avacuum manifold.

5C14. A method as in clause 4C14 wherein the wafer is supported on abelt moving to the vacuum manifold, and the vacuum is applied throughthe belt.

6C14. A method as in clause 5C14 wherein the separating comprises:

orienting the first scribe line at an angle relative to the vacuummanifold; and

beginning a cleaving at one end of the first scribe line.

7C14. A method as in clause 6C14 wherein the angle is substantiallyperpendicular.

8C14. A method as in clause 6C14 wherein the angle is other thansubstantially perpendicular.

9C14. A method as in clause 3C14 further comprising applying an uncuredelectrically conductive adhesive bonding material.

10C14. A method as in clause 9C14 wherein the first scribe line and theuncured electrically conductive adhesive bonding material are on a samesurface of the wafer.

11C14. A method as in clause 10C14 wherein the laser scribing avoidscuring the uncured conductive adhesive bonding material by selecting alaser power and/or a distance between the first scribe line and theuncured conductive adhesive bonding material.

12C14. A method as in clause 10C14 wherein the same surface is oppositea wafer surface supported by a belt moving the wafer to the curvedsurface.

13C14. A method as in clause 12C14 wherein the curved surface comprisesa vacuum manifold.

14C14. A method as in clause 9C14 wherein the applying occurs after thescribing.

15C14. A method as in clause 9C14 wherein the applying occurs after theseparating.

16C14. A method as in clause 9C14 wherein the applying comprises screenprinting.

17C14. A method as in clause 9C14 wherein the applying comprises ink jetprinting.

18C14. A method as in clause 9C14 wherein the applying comprisesdepositing using a mask.

19C14. A method as in clause 3C14 wherein the first scribe line isbetween,

a first metallization pattern on a surface of the wafer along a firstoutside edge, and

a second metallization pattern on the surface of the wafer along asecond outside edge.

20C14. A method as in clause 19C14 wherein the wafer further comprises athird metallization pattern on the surface of the semiconductor wafernot proximate to the first outside edge or to the second outside edge,and the method further comprises:

scribing a second scribe line between the third metallization patternand the second metallization pattern, such that the first scribe line isbetween the first metallization pattern and the third metallizationpattern; and

separating the wafer along the second scribe line to provide anothersolar cell strip.

21C14. A method as in clause 20C14 wherein a distance between the firstscribe line and the second scribe line forms a width defining an aspectratio of between about 1:2 and about 1:20 with a length of the wafercomprising about 125 mm or about 156 mm.

22C14. A method as in clause 19C14 wherein the first metallizationpattern comprises a finger pointing toward the second metallizationpattern.

23C14. A method as in clause 22C14 wherein the first metallizationpattern further comprises a bus bar intersecting the finger.

24C14. A method as in clause 23C14 wherein the bus bar is within 5 mm ofthe first outside edge.

25C14. A method as in clause 22C14 further comprising uncuredelectrically conductive adhesive bonding material in contact with thefinger.

26C14. A method as in clause 19C14 wherein the first metallizationpattern comprises a discrete contact pad.

27C14. A method as in clause 19C14 further comprising printing orelectroplating the first metallization pattern on the wafer.

28C14. A method as in clause 3 further comprising:

arranging the solar cell strip in a first super cell comprising at leastnineteen solar cell strips each having a breakdown voltage of at least10V, with long sides of adjacent solar cell strips overlapping theelectrically conductive adhesive bonding material disposed in between;and

curing the electrically conductive bonding material to bond adjacentoverlapping solar cell strips electrically connected in series.

29C14. A method as in clause 28C14 wherein the arranging comprisesforming a layered structure including an encapsulant, the method furthercomprising laminating the layered structure.

30C14. A method as in clause 29C14 wherein the curing occurs at leastpartially during the laminating

31C14. A method as in clause 29C14 wherein the curing occurs distinctfrom the laminating.

32C14. A method as in clause 29C14 wherein the encapsulant comprises athermoplastic olefin polymer.

33C14. A method as in clause 29C14 wherein the layered structurecomprises:

a white backing sheet; and

darkened stripes on the white backing sheet.

34C14. A method as in clause 28C14 wherein the arranging comprisesconfining a spreading of the electrically conductive adhesive bondingmaterial using a metallization pattern feature.

35C14. A method as in clause 34C14 wherein metallization pattern featureis on a front surface of the solar cell strip.

36C14. A method as in clause 34C14 wherein metallization pattern featureis on a back surface of the solar cell strip.

37C14. A method as in clause 28C14 further comprising applying theelectrically conductive adhesive bonding material between the firstsuper cell and an interconnect connecting a second super cell in series.

38C14. A method as in clause 28C14 further comprising forming a ribbonconductor between a single bypass diode of the first super cell, thesingle bypass diode located in a first junction box of a first solarmodule in mating arrangement with a second junction box of a secondsolar module.

39C14. A method as in clause 28C14 wherein:

the solar cell strip includes a first chamfered corner;

a long side of an overlapping solar cell strip of the plurality of solarcell strips, does not include a second chamfered corner; and

a width of the solar cell strip is greater than a width of theoverlapping solar cell strip, such that the solar cell strip and theoverlapping solar cell strip have approximately a same area.

40C14. A method as in clause 28C14 wherein:

the solar cell strip includes a first chamfered corner;

a long side of an overlapping solar cell strip of the plurality of solarcell strips, includes a second chamfered corner; and

the long side of the overlapping solar cell strip of the plurality ofsolar cell strips, overlaps a long side of the solar cell strip notincluding the first chamfered corner.

1C15. A method comprising:

forming a first metallization pattern along a first outside edge of afirst surface of a semiconductor wafer;

forming a second metallization pattern along a second outside edge ofthe first surface, the second outside edge opposite to the first outsideedge; and

forming a first scribe line between the first metallization pattern andthe second metallization pattern.

2C15. A method as in clause 1C15 wherein:

the first metallization pattern comprises a first finger pointing towardthe second metallization pattern; and

the second metallization pattern comprises a second finger pointingtoward the first metallization pattern.

3C15. A method as in clause 2C15 wherein:

the first metallization pattern further comprises a first bus barintersecting the first finger and located within 5 mm of the firstoutside edge; and

the second metallization pattern comprises a second bus bar intersectingthe second finger and located within 5 mm of the second outside edge.

4C15. A method as in clause 3C15 further comprising:

forming on the first surface, a third metallization pattern not alongthe first outside edge or along the second outside edge, the thirdmetallization pattern comprising,

a third bus bar parallel to the first bus bar, and

a third finger pointing toward the second metallization pattern; andforming a second scribe line between the third metallization pattern andthe second metallization pattern, wherein the first scribe line isbetween the first metallization pattern and the third metallizationpattern.

5C15. A method as in clause 4C15 wherein the first scribe line and thesecond scribe line are separated by a width having a ratio to a lengthof the semiconductor wafer, of between about 1:2 to about 1:20.

6C15. A method as in clause 5C15 wherein the length of the semiconductorwafer is about 156 mm or about 125 mm.

7C15. A method as in clause 4C15 wherein the semiconductor waferincludes chamfered corners.

8C15. A method as in clause 7C15 wherein:

the first scribe line defines with the first outside edge, a first solarcell region comprising two chamfered corners and the first metallizationpattern, the first solar cell region having a first area correspondingto a product of a length of the semiconductor wafer and a first width,minus a combined area of the two chamfered corners; and

the second scribe line defines with the first scribe line, a secondsolar cell region not including chamfered corners and including thethird metallization pattern, the second solar cell region having asecond area corresponding to a product of the length and a second widthnarrower than the first width, such that the first area and the secondarea are approximately the same.

9C15. A method as in clause 8C15 wherein the length is about 156 mm orabout 125 mm.

10C15. A method as in clause 4C15 wherein forming the first scribe lineand forming the second scribe line comprise laser scribing.

11C15. A method as in clause 4C15 wherein forming the firstmetallization pattern, forming the second metallization pattern, andforming the third metallization pattern, comprise printing.

12C15. A method as in clause 11C15 wherein forming the firstmetallization pattern, forming the second metallization pattern, andforming the third metallization pattern, comprise screen printing.

13C15. A method as in clause 11C15 wherein forming the firstmetallization pattern comprises forming a plurality of contact padscomprising silver.

14C15. A method as in clause 4C15 wherein forming the firstmetallization pattern, forming the second metallization pattern, andforming the third metallization pattern, comprise electroplating.

15C15. A method as in clause 14C15 wherein the first metallizationpattern, the second metallization pattern, and the third metallizationpattern comprise copper.

16C15. A method as in clause 4C15 wherein the first metallizationpattern comprises aluminum, tin, silver, copper, and/or a conductor lessexpensive than silver.

17C15. A method as in clause 4C15 wherein the semiconductor wafercomprises silicon.

18C15. A method as in clause 17C15 wherein the semiconductor wafercomprises crystalline silicon.

19C15. A method as in clause 4C15 further comprising forming a fourthmetallization pattern on a second surface of the semiconductor waferbetween the first outside edge and within 5 mm of a location of thesecond scribe line.

20C15. A method as in clause 4C15 wherein the first surface comprises afirst conductivity type and the second surface comprises a secondconductivity type opposite to the first conductivity type.

21C15. A method as in clause 4C15 wherein the fourth metallizationpattern comprises a contact pad.

22C15. A method as in clause 3C15 further comprising applying aconductive adhesive to the semiconductor wafer.

23C15. A method as in clause 22C15 further comprising applying theconductive adhesive in contact with the first finger.

24C15. A method as in clause 23C15 wherein applying the conductiveadhesive comprises screen printing or depositing utilizing a mask.

25C15. A method as in clause 3C15 further comprising separating thesemiconductor wafer along the first scribe line to form a first solarcell strip including the first metallization pattern.

26C15. A method as in clause 25C15 wherein the separating comprisesapplying a vacuum to the first scribe line.

27C15. A method as in clause 26C15 further comprising disposing thesemiconductor wafer on a belt moving to the vacuum.

28C15. A method as in clause 25C15 further comprising applying aconductive adhesive to the first solar cell strip.

29C15. A method as in clause 25C15 further comprising:

arranging the first solar cell strip in a first super cell comprising atleast nineteen solar cell strips each having a breakdown voltage of atleast 10V, with long sides of adjacent solar cell strips overlappingconductive adhesive disposed in between; and

curing the conductive adhesive to bond adjacent overlapping solar cellstrips electrically connected in series.

30C15. A method as in clause 29C15 wherein the arranging comprisesforming a layered structure including an encapsulant, the method furthercomprising laminating the layered structure.

31C15. A method as in clause 30C15 wherein the curing occurs at leastpartially during the laminating.

32C15. A method as in clause 30C15 wherein the curing occurs distinctfrom the laminating.

33C15. A method as in clause 30C15 wherein the encapsulant comprises athermoplastic olefin polymer.

34C15. A method as in clause 30C15 wherein the layered structurecomprises:

a white backing sheet; and

darkened stripes on the white backing sheet.

35C15. A method as in clause 29C15 wherein the arranging comprisesconfining a spreading of the conductive adhesive with a metallizationpattern feature.

36C15. A method as in clause 35C15 wherein the metallization patternfeature is on a front surface of the first solar cell strip.

37C15. A method as in clause 29C15 further comprising applying theconductive adhesive between the first super cell and an interconnectconnecting a second super cell in series.

38C15. A method as in clause 29C15 further comprising forming a ribbonconductor between a single bypass diode of the first super cell, thesingle bypass diode located in a first junction box of a first solarmodule in mating arrangement with a second junction box of a secondsolar module.

39C15. A method as in clause 29C15 wherein:

the first solar cell strip includes a first chamfered corner;

a long side of an overlapping solar cell strip of the first super cell,does not include a second chamfered corner; and

a width of the first solar cell strip is greater than a width of theoverlapping solar cell strip, such that the first solar cell strip andthe overlapping solar cell strip have approximately a same area.

40C15. A method as in clause 29C15 wherein:

the first solar cell strip includes a first chamfered corner;

a long side of an overlapping solar cell strip of the first super cell,includes a second chamfered corner; and

the long side of the overlapping solar cell strip, overlaps a long sideof the first solar cell strip not including the first chamfered corner.

1C16. A method comprising:

obtaining or providing a silicon wafer comprising a front surfacemetallization pattern including a first bus bar or row of contact padsarranged parallel to and adjacent a first outside edge of the wafer anda second bus bar or row of contact pads arranged parallel to andadjacent a second outside edge of the wafer opposite from and parallelto the first edge of the wafer;

separating the silicon wafer along one or more scribe lines parallel tothe first and second outside edges of the wafer to form a plurality ofrectangular solar cells, with the first bus bar or row of contact padsarranged parallel to and adjacent to a long outside edge of a first oneof the rectangular solar cells and the second bus bar or row of contactpads arranged parallel to and adjacent to a long outside edge of asecond one of the rectangular solar cells; and

arranging the rectangular solar cells in line with long sides ofadjacent solar cells overlapping and conductively bonded to each otherto electrically connect the solar cells in series to form a super cell;

wherein the first bus bar or row of contact pads on the first one of therectangular solar cells is overlapped by and conductively bonded to abottom surface of an adjacent rectangular solar cell in the super cell.

2C16. The method of clause 1C16, wherein the second bus bar or row ofcontact pads on the second one of the rectangular solar cells isoverlapped by and conductively bonded to a bottom surface of an adjacentrectangular solar cell in the super cell.

3C16. The method of clause 1C16, wherein the silicon wafer is a squareor pseudo square silicon wafer.

4C16. The method of clause 3C16, wherein the silicon wafer comprisessides of about 125 mm in length or about 156 mm in length.

5C16. The method of clause 3C16, wherein the ratio of length to width ofeach rectangular solar cell is between about 2:1 and about 20:1.

6C16. The method of clause 1C16, wherein the silicon wafer is acrystalline silicon wafer.

7C16. The method of clause 1C16, wherein the first bus bar or row ofcontact pads and the second bus bar or row of contact pads are locatedin edge regions of the silicon wafer that convert light to electricityless efficiently than central regions of the silicon wafer.

8C16. The method of clause 1C16, wherein the front surface metallizationpattern comprises a first plurality of parallel fingers electricallyconnected to the first bus bar or row of contact pads and extendinginward from the first outside edge of the wafer and a second pluralityof parallel fingers electrically connected to the second bus bar or rowof contact pads and extending inward from the second outside edge of thewafer.

9C16. The method of clause 1C16, wherein the front surface metallizationpattern comprises at least a third bus bar or row of contact padsoriented parallel to and located between the first bus bar or row ofcontact pads and the second bus bar or row of contact pad and a thirdplurality of parallel fingers oriented perpendicular to and electricallyconnected to the third bus bar or row of contact pads, and the third busbar or row of contact pads is arranged parallel to and adjacent a longoutside edge of a third one of the rectangular solar cells after thesilicon wafer is separated to form the plurality of rectangular solarcells.

10C16. The method of clause 1C16, comprising applying a conductiveadhesive to the first bus bar or row of contact pads by which toconductively bond the first rectangular solar cell to an adjacent solarcell.

11C16. The method of clause 10C16, wherein the metallization patterncomprises a barrier configured to confine spreading of the conductiveadhesive.

12C16. The method of clause 10C16, comprising applying the conductiveadhesive by screen printing.

13C16. The method of clause 10C16, comprising applying the conductiveadhesive by ink jet printing.

14C16. The method of clause 10C16, wherein the conductive adhesive isapplied before formation of the scribe lines in the silicon wafer.

15C16. The method of clause 1C16, wherein separating the silicon waferalong the one or more scribe lines comprises applying a vacuum between abottom surface of the silicon wafer and a curved supporting surface toflex the silicon wafer against the curved supporting surface and therebycleave the silicon wafer along the one or more scribe lines.

16C16. The method of clause 1C16 wherein:

the silicon wafer is a pseudo square silicon wafer comprising chamferedcorners and after separation of the silicon wafer to form the pluralityof rectangular solar cells one or more of the rectangular solar cellscomprises one or more of the chamfered corners; and

the spacing between scribe lines is selected to compensate for thechamfered corners by making the width perpendicular to the long axis ofthe rectangular solar cells that comprise chamfered corners greater thanthe width perpendicular to the long axis of the rectangular solar cellsthat lack chamfered corners, so that each of the plurality ofrectangular solar cells in the super cell has a front surface ofsubstantially the same area exposed to light in operation of the supercell.

17C16. The method of clause 1C16, comprising arranging the super cell ina layered structure between a transparent front sheet and a back sheetand laminating the layered structure.

18C16. The method of clause 17C16, wherein laminating the layeredstructure completes curing of a conductive adhesive disposed between theadjacent rectangular solar cells in the super cell to conductively bondthe adjacent rectangular solar cells to each other.

19C16. The method of clause 17C16, wherein the super cell is arranged inthe layered structure in one of two or more parallel rows of supercells, and the back sheet is a white sheet comprising parallel darkenedstripes having locations and widths corresponding to locations andwidths of gaps between the two or more rows of super cells such thatwhite portions of the back sheet are not visible through gaps betweenthe rows of super cells in the assembled module.

20C16. The method of clause 17C16, wherein the front sheet and the backsheet are glass sheets and the super cell is encapsulated in athermoplastic olefin layer sandwiched between the glass sheets.

21C16. The method of clause 1C16, comprising arranging the super cell ina first module comprising a junction box in mating arrangement with asecond junction box of a second solar module.

1D. A solar module comprising:

a plurality of super cells arranged in two or more parallel rows, eachsuper cell comprising a plurality of rectangular or substantiallyrectangular silicon solar cells arranged in line with long sides ofadjacent silicon solar cells overlapping and conductively bondeddirectly to each other to electrically connect the silicon solar cellsin series;

a first hidden tap contact pad located on a back surface of a firstsolar cell located at an intermediate position along a first one of thesuper cells; and

a first electrical interconnect conductively bonded to the first hiddentap contact pad;

wherein the first electrical interconnect comprises a stress relievingfeature accommodating differential thermal expansion between theinterconnect and the silicon solar cell to which it is bonded.

2D. The solar module of clause 1D, comprising a second hidden tapcontact pad located on a back surface of a second solar cell locatedadjacent the first solar cell at an intermediate position along a secondone of the super cells, wherein the first hidden tap contact pad iselectrically connected to the second hidden tap contact pad through thefirst electrical interconnect.

3D. The solar module of clause 2D, wherein the first electricalinterconnect extends across a gap between the first super cell and thesecond super cell and is conductively bonded to the second hidden tapcontact pad.

4D. The solar module of clause 1D, comprising a second hidden tapcontact pad located on a back surface of a second solar cell located atanother intermediate position along the first one of the super cells, asecond electrical interconnect conductively bonded to the second hiddentap contact pad, and a bypass diode electrically connected by the firstand second electrical interconnects in parallel with the solar cellslocated between the first hidden tap contact pad and the second hiddentap contact pad.

5D. The solar module of clause 1D, wherein the first hidden tap contactpad is one of a plurality of hidden tap contact pads arranged on theback surface of the first solar cell in a row running parallel to thelong axis of the first solar cell, and the first electrical interconnectis conductively bonded to each of the plurality of hidden contacts andsubstantially spans the length of the first solar cell along the longaxis.

6D. The solar module of clause 1D, wherein the first hidden tap contactpad is located adjacent a short side of the back surface of the firstsolar cell, the first electrical interconnect does not extendsubstantially inward from the hidden tap contact pad along the long axisof the solar cell, and a back surface metallization pattern on the firstsolar cell provides a conductive path to the interconnect having a sheetresistance less than or equal to about 5 Ohms per square.

7D. The solar module of clause 6D, wherein the sheet resistance is lessthan or equal to about 2.5 Ohms per square.

8D. The solar module of clause 6D, wherein the first interconnectcomprises two tabs positioned on opposite sides of the stress relievingfeature, and one of the tabs is conductively bonded to the first hiddentap contact pad.

9D. The solar module of clause 8D, wherein the two tabs are of differentlengths.

10D. The solar module of clause 1D, wherein the first electricalinterconnect comprises alignment features identifying a desiredalignment with the first hidden tap contact pad.

11D. The solar module of clause 1D, wherein the first electricalinterconnect comprises alignment features identifying a desiredalignment with an edge of the first super cell.

12D. The solar module of clause 1D, arranged in an overlapping shingledmanner with another solar module to which it is electrically connectedin an overlapping region.

13D. A solar module comprising:

a glass front sheet;

a back sheet;

a plurality of super cells arranged in two or more parallel rows betweenthe glass front sheet and the back sheet, each super cell comprising aplurality of rectangular or substantially rectangular silicon solarcells arranged in line with long sides of adjacent silicon solar cellsoverlapping and flexibly conductively bonded directly to each other toelectrically connect the silicon solar cells in series; and

a first flexible electrical interconnect rigidly conductively bonded toa first one of the super cells;

wherein the flexible conductive bonds between overlapping solar cellsprovide mechanical compliance to the super cells accommodating amismatch in thermal expansion between the super cells and the glassfront sheet in a direction parallel to the rows for a temperature rangeof about −40° C. to about 100° C. without damaging the solar module; and

wherein the rigid conductive bond between the first super cell and thefirst flexible electrical interconnect forces the first flexibleelectrical interconnect to accommodate a mismatch in thermal expansionbetween the first super cell and the first flexible interconnect in adirection perpendicular to the rows for a temperature range of about−40° C. to about 180° C. without damaging the solar module.

14D. The solar module of clause 13D, wherein the conductive bondsbetween overlapping adjacent solar cells within a super cell utilize adifferent conductive adhesive than the conductive bonds between thesuper cell and the flexible electrical interconnect

15D. The solar module of clause 14D, wherein both conductive adhesivescan be cured in the same processing step.

16D. The solar module of clause 13D, wherein the conductive bond at oneside of at least one solar cell within a super cell utilizes a differentconductive adhesive than the conductive bond at its other side

17D. The solar module of clause 16D, wherein both conductive adhesivescan be cured in the same processing step.

18D. The solar module of clause 13D, wherein the conductive bondsbetween overlapping adjacent solar cells accommodate differential motionbetween each cell and the glass front sheet of greater than or equal toabout 15 micron.

19D. The solar module of clause 13D, wherein the conductive bondsbetween overlapping adjacent solar cells have a thickness perpendicularto the solar cells of less than or equal to about 50 micron and athermal conductivity perpendicular to the solar cells greater than orequal to about 1.5 W/(meter-K).

20D. The solar module of clause 13D, wherein the first flexibleelectrical interconnect withstands thermal expansion or contraction ofthe first flexible interconnect of greater than or equal to about 40micron.

21D. The solar module of clause 13D, wherein the portion of the firstflexible electrical interconnect conductively bonded to the super cellis ribbon-like, formed from copper, and has a thickness perpendicular tothe surface of the solar cell to which it is bonded of less than orequal to about 50 microns.

22D. The solar module of clause 21D, wherein the portion of the firstflexible electrical interconnect conductively bonded to the super cellis ribbon-like, formed from copper, and has a thickness perpendicular tothe surface of the solar cell to which it is bonded of less than orequal to about 30 microns.

23D. The solar module of clause 21D, wherein the first flexibleelectrical interconnect comprises an integral conductive copper portionnot bonded to the solar cell and providing a higher conductivity thanthe portion of the first flexible electrical interconnect that isconductively bonded to the solar cell.

24D. The solar module of clause 21D, wherein the first flexibleelectrical interconnect has a width greater than or equal to about 10 mmin the plane of the surface of the solar cell in a directionperpendicular to the flow of current though the interconnect.

25D. The solar module of clause 21D, wherein the first flexibleelectrical interconnect is conductively bonded to a conductor proximateto the solar cell that provides higher conductivity than the firstelectrical interconnect.

26D. The solar module of clause 13D, arranged in an overlapping shingledmanner with another solar module to which it is electrically connectedin an overlapping region.

27D. A solar module comprising:

a plurality of super cells arranged in two or more parallel rows, eachsuper cell comprising a plurality of rectangular or substantiallyrectangular silicon solar cells arranged in line with long sides ofadjacent silicon solar cells overlapping and conductively bondeddirectly to each other to electrically connect the silicon solar cellsin series; and

a hidden tap contact pad which does not conduct significant current innormal operation located on a back surface of a first solar cell;

wherein the first solar cell is located at an intermediate positionalong a first one of the super cells in a first one of the rows of supercells and the hidden tap contact pad is electrically connected inparallel to at least a second solar cell in a second one of the rows ofsuper cells.

28D. The solar module of clause 27D, comprising an electricalinterconnect bonded to the hidden tap contact pad and electricallyinterconnecting the hidden tap contact pad to the second solar cell,wherein the electrical interconnect does not substantially span thelength of the first solar cell and a back surface metallization patternon the first solar cell provides a conductivity path to the hidden tapcontact pad having a sheet resistance less than or equal to about 5 Ohmsper square.

29D. The solar module of clause 27D, wherein the plurality of supercells are arranged in three or more parallel rows spanning the width ofthe solar module perpendicular to the rows, and the hidden tap contactpad is electrically connected to a hidden contact pad on at least onesolar cell in each of the rows of super cells to electrically connectthe rows of super cells in parallel, and at least one bus connection toat least one of the hidden tap contact pads or to an interconnectbetween hidden tap contact pads connects to a bypass diode or otherelectronic device.

30D. The solar module of clause 27D, comprising a flexible electricalinterconnect conductively bonded to the hidden tap contact pad toelectrically connect it to the second solar cell, wherein:

the portion of the flexible electrical interconnect conductively bondedto the hidden tap contact pad is ribbon-like, formed from copper, andhas a thickness perpendicular to the surface of the solar cell to whichit is bonded of less than or equal to about 50 microns; and

the conductive bond between the hidden tap contact pad and the flexibleelectrical interconnect forces the flexible electrical interconnect towithstand a mismatch in thermal expansion between the first solar celland the flexible interconnect, and to accommodate relative motionbetween the first solar cell and the second solar cell resulting fromthermal expansion, for a temperature range of about −40° C. to about180° C. without damaging the solar module.

31D. The solar module of clause 27D, wherein in operation of the solarmodule the first hidden contact pad may conduct a current greater thanthe current generated in any single one of the solar cells.

32D. The solar module of clause 27D, wherein the front surface of thefirst solar cell overlying the first hidden tap contact pad is notoccupied by contact pads or any other interconnect features.

33D. The solar module of clause 27D, wherein any area of the frontsurface of the first solar cell which is not overlapped by a portion ofan adjacent solar cell in the first super cell is not occupied bycontact pads or any other interconnect features.

34D. The solar module of clause 27D, wherein in each super cell most ofthe cells do not have hidden tap contact pads.

35D. The solar module of clause 34D, wherein the cells that have hiddentap contact pads have a larger light collection area than the cells thatdo not have hidden tap contact pads.

36D. The solar module of clause 27D, arranged in an overlapping shingledmanner with another solar module to which it is electrically connectedin an overlapping region.

37D. A solar module comprising:

a glass front sheet;

a back sheet;

a plurality of super cells arranged in two or more parallel rows betweenthe glass front sheet and the back sheet, each super cell comprising aplurality of rectangular or substantially rectangular silicon solarcells arranged in line with long sides of adjacent silicon solar cellsoverlapping and flexibly conductively bonded directly to each other toelectrically connect the silicon solar cells in series; and

a first flexible electrical interconnect rigidly conductively bonded toa first one of the super cells;

wherein the flexible conductive bonds between overlapping solar cellsare formed from a first conductive adhesive and have a shear modulusless than or equal to about 800 megapascals; and

wherein the rigid conductive bond between the first super cell and thefirst flexible electrical interconnect is formed from a secondconductive adhesive and has a shear modulus of greater than or equal toabout 2000 megapascals.

38D. The solar module of clause 37D, wherein the first conductiveadhesive and the second conductive adhesive are different, and bothconductive adhesives can be cured in the same processing step

39D. The solar module of clause 37D, wherein the conductive bondsbetween overlapping adjacent solar cells have a thickness perpendicularto the solar cells of less than or equal to about 50 micron and athermal conductivity perpendicular to the solar cells greater than orequal to about 1.5 W/(meter-K).

40D. The solar module of clause 37D, arranged in an overlapping shingledmanner with another solar module to which it is electrically connectedin an overlapping region.

1E. A solar module comprising: a number N greater than or equal to about150 rectangular or substantially rectangular silicon solar cellsarranged as a plurality of super cells in two or more parallel rows,each super cell comprising a plurality of the silicon solar cellsarranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series; wherein the super cells areelectrically connected to provide a high direct current voltage ofgreater than or equal to about 90 volts.

2E. The solar module of clause 1E, comprising one or more flexibleelectrical interconnects arranged to electrically connect the pluralityof super cells in series to provide the high direct current voltage.

3E. The solar module of clause 2E, comprising module level powerelectronics including an inverter that converts the high direct currentvoltage to an alternating current voltage.

4E. The solar module of clause 3E, wherein the module level powerelectronics sense the high direct current voltage and operate the moduleat an optimum current-voltage power point.

5E. The solar module of clause 1E, comprising module level powerelectronics electrically connected to individual pairs of adjacentseries connected rows of super cells, electrically connecting one ormore of the pairs of rows of super cells in series to provide the highdirect current voltage, and comprising an inverter that converts thehigh direct current voltage to an alternating current voltage.

6E. The solar module of clause 5E, wherein the module level powerelectronics sense the voltage across each individual pair of rows ofsuper cells and operate each individual pair of rows of super cells atan optimum current-voltage power point.

7E. The solar module of clause 6E, wherein the module level powerelectronics switch an individual pair of rows of super cells out of acircuit providing the high direct current voltage if the voltage acrossthe pair of rows is below a threshold value.

8E. The solar module of clause 1E, comprising module level powerelectronics electrically connected to each individual row of supercells, electrically connecting two or more of the rows of super cells inseries to provide the high direct current voltage, and comprising aninverter that converts the high direct current voltage to an alternatingcurrent voltage.

9E. The solar module of clause 8E, wherein the module level powerelectronics sense the voltage across each individual row of super cellsand operate each individual row of super cells at an optimumcurrent-voltage power point.

10E. The solar module of clause 9E, wherein the module level powerelectronics switch an individual row of super cells out of a circuitproviding the high direct current voltage if the voltage across the rowof super cells is below a threshold value.

11E. The solar module of clause 1E, comprising module level powerelectronics electrically connected to each individual super cell,electrically connecting two or more of the super cells in series toprovide the high direct current voltage, and comprising an inverter thatconverts the high direct current voltage to an alternating currentvoltage.

12E. The solar module of clause 11E, wherein the module level powerelectronics sense the voltage across each individual super cell andoperate each individual super cell at an optimum current-voltage powerpoint.

13E. The solar module of clause 12E, wherein the module level powerelectronics switch an individual super cell out of a circuit providingthe high direct current voltage if the voltage across the super cell isbelow a threshold value.

14E. The solar module of clause 1E, wherein each super cell iselectrically segmented into a plurality of segments by hidden taps, thesolar module comprising module level power electronics electricallyconnected to each segment of each super cell through the hidden taps,electrically connecting two or segments in series to provide the highdirect current voltage, and comprising an inverter that converts thehigh direct current voltage to an alternating current voltage.

15E. The solar module of clause 14E, wherein the module level powerelectronics sense the voltage across each individual segment of eachsuper cell and operate each individual segment at an optimumcurrent-voltage power point.

16E. The solar module of clause 15E, wherein the module level powerelectronics switch an individual segment out of a circuit providing thehigh direct current voltage if the voltage across the segment is below athreshold value.

17E. The solar module of any of clauses 4E, 6E, 9E, 12E, or 15E, whereinthe optimum current-voltage power point is a maximum current-voltagepower point.

18E. The solar module of any of clauses 3E-17E, wherein the module levelpower electronics lack a direct current to direct current boostcomponent.

19E. The solar module of any of clauses 1E-18E, wherein N is greaterthan or equal to about 200, greater than or equal to about 250, greaterthan or equal to about 300, greater than or equal to about 350, greaterthan or equal to about 400, greater than or equal to about 450, greaterthan or equal to about 500, greater than or equal to about 550, greaterthan or equal to about 600 greater than or equal to about 650, orgreater than or equal to about 700.

20E. The solar module of any of clauses 1E-19E, wherein the high directcurrent voltage is greater than or equal to about 120 volts, greaterthan or equal to about 180 volts, greater than or equal to about 240volts, greater than or equal to about 300 volts, greater than or equalto about 360 volts, greater than or equal to about 420 volts, greaterthan or equal to about 480 volts, greater than or equal to about 540volts, or greater than or equal to about 600 volts.

21E. A solar photovoltaic system comprising:

two or more solar modules electrically connected in parallel; and

an inverter;

wherein each solar module comprises a number N greater than or equal toabout 150 rectangular or substantially rectangular silicon solar cellsarranged as a plurality of super cells in two or more parallel rows,each super cell in each module comprises two or more of the siliconsolar cells in that module arranged in line with long sides of adjacentsilicon solar cells overlapping and conductively bonded to each other toelectrically connect the silicon solar cells in series, and in eachmodule the super cells are electrically connected to provide a highvoltage direct current module output of greater than or equal to about90 volts; and

wherein the inverter is electrically connected to the two or more solarmodules to convert their high voltage direct current output to analternating current.

22E. The solar photovoltaic system of clause 21E, wherein each solarmodule comprises one or more flexible electrical interconnects arrangedto electrically connect the super cells in the solar module in series toprovide the solar module's high voltage direct current output.

23E. The solar photovoltaic system of clause 21E, comprising at least athird solar module electrically connected in series with a first one ofthe two or more solar modules electrically connected in parallel,wherein the third solar module comprises a number N′ greater than orequal to about 150 rectangular or substantially rectangular siliconsolar cells arranged as a plurality of super cells in two or moreparallel rows, each super cell in the third solar module comprises twoor more of the silicon solar cells in that module arranged in line withlong sides of adjacent silicon solar cells overlapping and conductivelybonded to each other to electrically connect the silicon solar cells inseries, and in the third solar module the super cells are electricallyconnected to provide a high voltage direct current module output ofgreater than or equal to about 90 volts.

24E. The solar photovoltaic system of clause 23E, comprising at least afourth solar module electrically connected in series with a second oneof the two or more solar modules electrically connected in parallel,wherein the fourth solar module comprises a number N″ greater than orequal to about 150 rectangular or substantially rectangular siliconsolar cells arranged as a plurality of super cells in two or moreparallel rows, each super cell in the fourth solar module comprises twoor more of the silicon solar cells in that module arranged in line withlong sides of adjacent silicon solar cells overlapping and conductivelybonded to each other to electrically connect the silicon solar cells inseries, and in the fourth solar module the super cells are electricallyconnected to provide a high voltage direct current module output ofgreater than or equal to about 90 volts.

25E. The solar photovoltaic system of clauses 21E-24E, comprising fusesarranged to prevent a short circuit occurring in any one of the solarmodules from dissipating power generated in the other solar modules.

26E. The solar photovoltaic system of any of clauses 21E-25E, comprisingblocking diodes arranged to prevent a short circuit occurring in any oneof the solar modules from dissipating power generated in other ones ofthe solar modules.

27E. The solar photovoltaic system of any of clauses 21E-26E, comprisingpositive and negative buses to which the two or more solar modules areelectrically connected in parallel and to which the inverter iselectrically connected.

28E. The solar photovoltaic system of any of clauses 21E-26E, comprisinga combiner box to which the two or more solar modules are electricallyconnected by a separate conductor, the combiner box electricallyconnecting the solar modules in parallel.

29E. The solar photovoltaic system of clause 28E, wherein the combinerbox comprises fuses arranged to prevent a short circuit occurring in anyone of the solar modules from dissipating power generated in the othersolar modules.

30E. The solar photovoltaic system of clause 28E or clause 29E, whereinthe combiner box comprises blocking diodes arranged to prevent a shortcircuit occurring in any one of the solar modules from dissipating powergenerated in other ones of the solar modules.

31E. The solar photovoltaic system of any of clauses 21E-30E, whereinthe inverter is configured to operate the solar modules at a directcurrent voltage above a minimum value set to avoid reverse biasing amodule.

32E. The solar photovoltaic system of any of clauses 21E-30E, whereinthe inverter is configured to recognize a reverse bias condition andoperate the solar modules at a voltage that avoids the reverse biascondition.

33E. The solar module of any of clauses 21E-32E, wherein N is greaterthan or equal to about 200, greater than or equal to about 250, greaterthan or equal to about 300, greater than or equal to about 350, greaterthan or equal to about 400, greater than or equal to about 450, greaterthan or equal to about 500, greater than or equal to about 550, greaterthan or equal to about 600 greater than or equal to about 650, orgreater than or equal to about 700.

34E. The solar module of any of clauses 21E-33E, wherein the high directcurrent voltage is greater than or equal to about 120 volts, greaterthan or equal to about 180 volts, greater than or equal to about 240volts, greater than or equal to about 300 volts, greater than or equalto about 360 volts, greater than or equal to about 420 volts, greaterthan or equal to about 480 volts, greater than or equal to about 540volts, or greater than or equal to about 600 volts.

35E. The solar photovoltaic system of any of clauses 21E-34E, positionedon a roof top.

36E. A solar photovoltaic system comprising:

a first solar module comprising a number N greater than or equal toabout 150 rectangular or substantially rectangular silicon solar cellsarranged as a plurality of super cells in two or more parallel rows,each super cell comprising a plurality of the silicon solar cellsarranged in line with long sides of adjacent silicon solar cellsoverlapping and conductively bonded to each other to electricallyconnect the silicon solar cells in series; and

an inverter;

wherein the super cells are electrically connected to provide a highdirect current voltage of greater than or equal to about 90 volts to theinverter, which converts the direct current to an alternating current.

37E. The solar photovoltaic system of clause 36E, wherein the inverteris a microinverter integrated with the first solar module.

38E. The solar photovoltaic system of clause 36E, wherein the firstsolar module comprises one or more flexible electrical interconnectsarranged to electrically connect the super cells in the solar module inseries to provide the solar module's high voltage direct current output.

39E. The solar photovoltaic system of any of clauses 36E-38E, comprisingat least a second solar module electrically connected in series with thefirst solar module, wherein the second solar module comprises a numberN′ greater than or equal to about 150 rectangular or substantiallyrectangular silicon solar cells arranged as a plurality of super cellsin two or more parallel rows, each super cell in the second solar modulecomprises two or more of the silicon solar cells in that module arrangedin line with long sides of adjacent silicon solar cells overlapping andconductively bonded to each other to electrically connect the siliconsolar cells in series, and in the second solar module the super cellsare electrically connected to provide a high voltage direct currentmodule output of greater than or equal to about 90 volts.

40E. The solar module of any of clauses 36E-39E, wherein the inverterlacks a direct current to direct current boost component.

41E. The solar module of any of clauses 36E-40E, wherein N is greaterthan or equal to about 200, greater than or equal to about 250, greaterthan or equal to about 300, greater than or equal to about 350, greaterthan or equal to about 400, greater than or equal to about 450, greaterthan or equal to about 500, greater than or equal to about 550, greaterthan or equal to about 600 greater than or equal to about 650, orgreater than or equal to about 700.

42E. The solar module of any of clauses 36E-41E, wherein the high directcurrent voltage is greater than or equal to about 120 volts, greaterthan or equal to about 180 volts, greater than or equal to about 240volts, greater than or equal to about 300 volts, greater than or equalto about 360 volts, greater than or equal to about 420 volts, greaterthan or equal to about 480 volts, greater than or equal to about 540volts, or greater than or equal to about 600 volts.

43E. A solar module comprising:

a number N greater than or equal to about 250 rectangular orsubstantially rectangular silicon solar cells arranged as a plurality ofseries-connected super cells in two or more parallel rows, each supercell comprising a plurality of the silicon solar cells arranged in linewith long sides of adjacent silicon solar cells overlapping andconductively bonded directly to each other with an electrically andthermally conductive adhesive to electrically connect the silicon solarcells in the super cell in series; and

less than one bypass diode per 25 solar cells;

wherein the electrically and thermally conductive adhesive forms bondsbetween adjacent solar cells having a thickness perpendicular to thesolar cells of less than or equal to about 50 micron and a thermalconductivity perpendicular to the solar cells greater than or equal toabout 1.5 W/(meter-K).

44E. The solar module of clause 43E, wherein the super cells areencapsulated in a thermoplastic olefin layer between front and backsheets.

45E. The solar module of clause 43E, wherein the super cells areencapsulated in between glass front and back sheets.

46E. The solar module of clause 43E, comprising less than one bypassdiode per 30 solar cells, or less than one bypass diode per 50 solarcells, or less than one bypass diode per 100 solar cells, or only asingle bypass diode, or not comprising a bypass diode.

47E. The solar module of clause 43E, comprising no bypass diodes, oronly a single bypass diode, or not more than three bypass diodes, or notmore than six bypass diodes, or not more than ten bypass diodes.

48E. The solar module of clause 43E, wherein the conductive bondsbetween overlapping solar cells provide mechanical compliance to thesuper cells accommodating a mismatch in thermal expansion between thesuper cells and the glass front sheet in a direction parallel to therows for a temperature range of about −40° C. to about 100° C. withoutdamaging the solar module.

49E. The solar module of any of clauses 43E-48E, wherein N is greaterthan or equal to about 300, greater than or equal to about 350, greaterthan or equal to about 400, greater than or equal to about 450, greaterthan or equal to about 500, greater than or equal to about 550, greaterthan or equal to about 600 greater than or equal to about 650, orgreater than or equal to about 700.

50E. The solar module of any of clauses 43E-49E, wherein the super cellsare electrically connected to provide a high direct current voltage ofgreater than or equal to about 120 volts, greater than or equal to about180 volts, greater than or equal to about 240 volts, greater than orequal to about 300 volts, greater than or equal to about 360 volts,greater than or equal to about 420 volts, greater than or equal to about480 volts, greater than or equal to about 540 volts, or greater than orequal to about 600 volts.

51E. A solar energy system comprising:

the solar module of clause 43E; and

an inverter electrically connected to the solar module and configured toconvert a DC output from the solar module to provide an AC output.

52E. The solar energy system of clause 51E, wherein the inverter lacks aDC to DC boost component.

53E. The solar energy system of clause 51E, wherein the inverter isconfigured to operate the solar module at a direct current voltage abovea minimum value set to avoid reverse biasing a solar cell.

54E. The solar energy system of clause 53E, wherein the minimum voltagevalue is temperature dependent.

55E. The solar energy system of clause 51E, wherein the inverter isconfigured to recognize a reverse bias condition and operate the solarmodule at a voltage that avoids the reverse bias condition.

56E. The solar energy system of clause 55E, wherein the inverter isconfigured to operate the solar module in a local maximum region of thesolar module's voltage-current power curve to avoid the reverse biascondition.

57E. The solar energy system of any of clauses 51E-56E, wherein theinverter is a microinverter integrated with the solar module.

1F. A method of manufacturing solar cells, the method comprising:

advancing a solar cell wafer along a curved surface; and

applying a vacuum between the curved surface and a bottom surface of thesolar cell wafer to flex the solar cell wafer against the curved surfaceand thereby cleave the solar cell wafer along one or more previouslyprepared scribe lines to separate a plurality of solar cells from thesolar cell wafer.

2F. The method of clause 1F, wherein the curved surface is a curvedportion of an upper surface of a vacuum manifold that applies the vacuumto the bottom surface of the solar cell wafer.

3F. The method of clause 2F, wherein the vacuum applied to the bottomsurface of the solar cell wafer by the vacuum manifold varies along thedirection of travel of the solar cell wafer and is strongest in a regionof the vacuum manifold in which the solar cell wafer is cleaved.

4F. The method of clause 2F or clause 3F, comprising transporting thesolar cell wafer along the curved upper surface of the vacuum manifoldwith a perforated belt, wherein the vacuum is applied to the bottomsurface of the solar cell wafer through perforations in the perforatedbelt.

5F. The method of clause 4F, wherein the perforations in the belt arearranged so that leading and trailing edges of the solar cell waferalong the direction of travel of the in the solar cell wafer mustoverlie at least one perforation in the belt.

6F. The method of any of clauses 2F-5F, comprising advancing the solarcell wafer along a flat region of the upper surface of the vacuummanifold to reach a transitional curved region of the upper surface ofthe vacuum manifold having a first curvature, and then advancing thesolar cell wafer into a cleave region of the upper surface of the vacuummanifold where the solar cell wafer is cleaved, the cleave region of thevacuum manifold having a second curvature tighter than the firstcurvature.

7F. The method of clause 6F, wherein the curvature of the transitionalregion is defined by a continuous geometric function of increasingcurvature.

8F. The method of clause 7F, wherein the curvature of the cleave regionis defined by the continuous geometric function of increasing curvature.

9F. The method of clause 6F, comprising advancing the cleaved solarcells into a post-cleave region of the vacuum manifold having a thirdcurvature tighter than the second curvature.

10F. The method of clause 9F, wherein the curvatures of the transitionalcurved region, the cleave region, and the post cleave region are definedby a single continuous geometric function of increasing curvature.

11F. The method of clause 7F, clause 8F, or clause 10F, wherein thecontinuous geometric function of increasing curvature is a clothoid.

12F. The method of any of clauses 1F-11F, comprising applying a strongervacuum between the solar cell wafer and the curved surface at one end ofeach scribe line then at the opposite end of each scribe line to providean asymmetric stress distribution along each scribe line that promotesnucleation and propagation of a single cleaving crack along each scribeline.

13F. The method of any of clauses 1F-12F, comprising removing thecleaved solar cells from the curved surface, wherein edges of thecleaved solar cells do not touch prior to removal of the solar cellsfrom the curved surface.

14F. The method of any of clauses 1F-13F, comprising:

laser scribing the scribe lines onto the solar cell wafer; and

applying an electrically conductive adhesive bonding material toportions of a top surface of the solar cell wafer prior to cleaving thesolar cell wafer along the scribe lines;

wherein each cleaved solar cell comprises a portion of the electricallyconductive adhesive bonding material disposed along a cleaved edge ofits top surface.

15F. The method of clause 14F, comprising laser scribing the scribelines, then applying the electrically conductive adhesive bondingmaterial.

16F. The method of clause 14F, comprising applying the electricallyconductive adhesive bonding material, then laser scribing the scribelines.

17F. A method of making a string of solar cells from cleaved solar cellsmanufactured by the method of any of clauses 14F-16F, wherein thecleaved solar cells are rectangular, the method comprising:

arranging the plurality of rectangular solar cells in line with longsides of adjacent rectangular solar cells overlapping in a shingledmanner with a portion of the electrically conductive adhesive bondingmaterial disposed in between; and

curing the electrically conductive bonding material, thereby bondingadjacent overlapping rectangular solar cells to each other andelectrically connecting them in series.

18F. The method of any of clauses 1F-17F, wherein the solar cell waferis a square or pseudo square silicon solar cell wafer.

1G. A method of making a string of solar cells, the method comprising:

forming a rear surface metallization pattern on each of one or moresquare solar cells;

stencil printing a complete front surface metallization pattern on eachof the one or more square solar cells using a single stencil in a singlestencil printing step;

separating each square solar cell into two or more rectangular solarcells to form from the one or more square solar cells a plurality ofrectangular solar cells each comprising a complete front surfacemetallization pattern and a rear surface metallization pattern;

arranging the plurality of rectangular solar cells in line with longsides of adjacent rectangular solar cells overlapping in a shingledmanner; and

conductively bonding the rectangular solar cells in each pair ofadjacent overlapping rectangular solar cells to each other with anelectrically conductive bonding material disposed between them toelectrically connect the front surface metallization pattern of one ofthe rectangular solar cells in the pair to the rear surfacemetallization pattern of the other of the rectangular solar cells in thepair, thereby electrically connecting the plurality of rectangular solarcells in series.

2G. The method of clause 1G, wherein all portions of the stencil thatdefine one or more features of the front surface metallization patternon the one or more square solar cells are constrained by physicalconnections to other portions of the stencil to lie in a plane of thestencil during stencil printing.

3G. The method of clause 1G, wherein the front surface metallizationpattern on each rectangular solar cell comprises a plurality of fingersoriented perpendicularly to the long sides of the rectangular solar celland none of the fingers in the front surface metallization pattern arephysically connected to each other by the front surface metallizationpattern.

4G. The method of clause 3G, wherein the fingers have widths of about 10microns to about 90 microns.

5G. The method of clause 3G, wherein the fingers have widths of about 10microns to about 50 microns.

6G. The method of clause 3G, wherein the fingers have widths of about 10microns to about 30 microns.

7G. The method of clause 3G, wherein the fingers have heightsperpendicular to the front surface of the rectangular solar cell ofabout 10 microns to about 50 microns.

8G. The method of clause 3G, wherein the fingers have heightsperpendicular to the front surface of the rectangular solar of about 30microns or greater.

9G. The method of clause 3G, wherein the front surface metallizationpattern on each rectangular solar cell comprises a plurality of contactpads arranged parallel to and adjacent to an edge of a long side of therectangular solar cell, with each contact pad located at an end of acorresponding finger.

10G. The method of clause 3G, wherein the rear surface metallizationpattern on each rectangular solar cell comprises a plurality of contactpads arranged in a row parallel to and adjacent to an edge of a longside of the rectangular solar cell, and each pair of adjacentoverlapping rectangular solar cells is arranged with each of the rearsurface contact pads on one of the pair of rectangular solar cellsaligned with and electrically connected to a corresponding finger in thefront surface metallization pattern on the other of the rectangularsolar cells in the pair.

11G. The method of clause 3G, wherein the rear surface metallizationpattern on each rectangular solar cell comprises a bus bar runningparallel to and adjacent to an edge of a long side of the rectangularsolar cell, and each pair of adjacent overlapping rectangular solarcells is arranged with the bus bar on one of the pair of rectangularsolar cells overlapping and electrically connected to the fingers in thefront surface metallization pattern on the other of the rectangularsolar cells in the pair.

12G. The method of clause 3G, wherein:

the front surface metallization pattern on each rectangular solar cellcomprises a plurality of contact pads arranged parallel to and adjacentto an edge of a long side of the rectangular solar cell, with eachcontact pad located at an end of a corresponding finger;

the rear surface metallization pattern on each rectangular solar cellcomprises a plurality of contact pads arranged in a row parallel to andadjacent to an edge of a long side of the rectangular solar cell; and

each pair of adjacent overlapping rectangular solar cells is arrangedwith each of the rear surface contact pads on one of the pair ofrectangular solar cells overlapping with and electrically connected to acorresponding contact pad in the front surface metallization pattern onthe other of the rectangular solar cells in the pair.

13G. The method of clause 12G, wherein the rectangular solar cells ineach pair of adjacent overlapping rectangular solar cells areconductively bonded to each other by discrete portions of electricallyconductive bonding material disposed between the overlapping front andrear surface contact pads.

14G. The method of clause 3G, wherein the rectangular solar cells ineach pair of adjacent overlapping rectangular solar cells areconductively bonded to each other by discrete portions of electricallyconductive bonding material disposed between overlapped ends of thefingers in the front surface metallization pattern of one of the pair ofrectangular solar cells and the rear surface metallization pattern ofthe other of the pair of rectangular solar cells.

15G. The method of clause 3G, wherein the rectangular solar cells ineach pair of adjacent overlapping rectangular solar cells areconductively bonded to each other by a dashed or continuous line ofelectrically conductive bonding material disposed between the overlappedends of the fingers in the front surface metallization pattern of one ofthe pair of rectangular solar cells and the rear surface metallizationpattern of the other of the pair of rectangular solar cells, the dashedor continuous line of electrically conductive bonding materialelectrically interconnecting one or more of the fingers.

16G. The method of clause 3G wherein:

the front surface metallization pattern on each rectangular solar cellcomprises a plurality of contact pads arranged parallel to and adjacentto an edge of a long side of the rectangular solar cell, with eachcontact pad located at an end of a corresponding finger; and

the rectangular solar cells in each pair of adjacent overlappingrectangular solar cells are conductively bonded to each other bydiscrete portions of electrically conductive bonding material disposedbetween the contact pads in the front surface metallization pattern ofone of the pair of rectangular solar cells and the rear surfacemetallization pattern of the other of the pair of rectangular solarcells.

17G. The method of clause 3G wherein:

the front surface metallization pattern on each rectangular solar cellcomprises a plurality of contact pads arranged parallel to and adjacentto an edge of a long side of the rectangular solar cell, with eachcontact pad located at an end of a corresponding finger; and

the rectangular solar cells in each pair of adjacent overlappingrectangular solar cells are conductively bonded to each other by adashed or continuous line of electrically conductive bonding materialdisposed between the contact pads in the front surface metallizationpattern of one of the pair of rectangular solar cells and the rearsurface metallization pattern of the other of the pair of rectangularsolar cells, the dashed or continuous line of electrically conductivebonding material electrically interconnecting one or more of thefingers.

18G. The method of any of clauses 1G-17G, wherein the front surfacemetallization pattern is formed from silver paste.

1H. A method of manufacturing a plurality of solar cells, the methodcomprising:

depositing one or more front surface amorphous silicon layers on a frontsurface of a crystalline silicon wafer, the front surface amorphoussilicon layers to be illuminated by light in operation of the solarcells;

depositing one or more rear surface amorphous silicon layers on a rearsurface of the crystalline silicon wafer on the opposite side of thecrystalline silicon wafer from the front surface;

patterning the one or more front surface amorphous silicon layers toform one or more front surface trenches in the one or more front surfaceamorphous silicon layers;

depositing a front surface passivating layer over the one or more frontsurface amorphous silicon layers and in the front surface trenches;

patterning the one or more rear surface amorphous silicon layers to formone or more rear surface trenches in the one or more rear surfaceamorphous silicon layers, each of the one or more rear surface trenchesformed in line with a corresponding one of the front surface trenches;

depositing a rear surface passivating layer over the one or more rearsurface amorphous silicon layers and in the rear surface trenches; and

cleaving the crystalline silicon wafer at one or more cleavage planes,each cleavage plane centered or substantially centered on a differentpair of corresponding front and rear surface trenches.

2H. The method of clause 1H, comprising forming the one or more frontsurface trenches to penetrate the front surface amorphous silicon layersto reach the front surface of the crystalline silicon wafer.

3H. The method of clause 1H, comprising forming the one or more rearsurface trenches to penetrate the one or more rear surface amorphoussilicon layers to reach the rear surface of the crystalline siliconwafer.

4H. The method of clause 1H, comprising forming the front surfacepassivating layer and the rear surface passivating layer from atransparent conductive oxide.

5H. The method of clause 1H, comprising using a laser to induce thermalstress in the crystalline silicon wafer to cleave the crystallinesilicon wafer at the one or more cleavage planes.

6H. The method of clause 1H, comprising mechanically cleaving thecrystalline silicon wafer at the one or more cleavage planes.

7H. The method of clause 1H, wherein the one or more front surfaceamorphous crystalline silicon layers form an n-p junction with thecrystalline silicon wafer.

8H. The method of clause 7H, comprising cleaving the crystalline siliconwafer from its rear surface side.

9H. The method of clause 1H, wherein the one or more rear surfaceamorphous crystalline silicon layers form an n-p junction with thecrystalline silicon wafer.

10H. The method of clause 9H, comprising cleaving the crystallinesilicon wafer from its front surface side.

11H. A method of manufacturing a plurality of solar cells, the methodcomprising:

forming one or more trenches in a first surface of a crystalline siliconwafer;

depositing one or more amorphous silicon layers on the first surface ofthe crystalline silicon wafer;

depositing a passivating layer in the trenches and on the one or moreamorphous silicon layers on the first surface of the crystalline siliconwafer;

depositing one or more amorphous silicon layers on a second surface ofthe crystalline silicon wafer on the opposite side of the crystallinesilicon wafer from the first surface;

cleaving the crystalline silicon wafer at one or more cleavage planes,each cleavage plane centered or substantially centered on a differentone of the one or more trenches.

12H. The method of clause 11H, comprising forming the passivating layerfrom a transparent conductive oxide.

13H. The method of clause 11H, comprising using a laser to inducethermal stress in the crystalline silicon wafer to cleave thecrystalline silicon wafer at the one or more cleavage planes.

14H. The method of clause 11H, comprising mechanically cleaving thecrystalline silicon wafer at the one or more cleavage planes.

15H. The method of clause 11H, wherein the one or more first surfaceamorphous crystalline silicon layers form an n-p junction with thecrystalline silicon wafer.

16H. The method of clause 11H, wherein the one or more second surfaceamorphous crystalline silicon layers form an n-p junction with thecrystalline silicon wafer.

17H. The method of clause 11H, wherein the first surface of thecrystalline silicon wafer is to be illuminated by light in operation ofthe solar cells.

18H. The method of clause 11H, wherein the second surface of thecrystalline silicon wafer is to be illuminated by light in operation ofthe solar cells.

19H. A solar panel comprising:

a plurality of super cells, each super cell comprising a plurality ofsolar cells arranged in line with end portions of adjacent solar cellsoverlapping in a shingled manner and conductively bonded to each otherto electrically connect the solar cells in series;

wherein each solar cell comprises a crystalline silicon base, one ormore first surface amorphous silicon layers disposed on a first surfaceof the crystalline silicon base to form an n-p junction, one or moresecond surface amorphous silicon layers disposed on a second surface ofthe crystalline silicon base on the opposite side of the crystallinesilicon base from the first surface, and passivating layers preventingcarrier recombination at edges of the first surface amorphous siliconlayers, at edges of the second surface amorphous silicon layers, or atedges of the first surface amorphous silicon layers and edges of thesecond surface amorphous silicon layers.

20H. The solar panel of clause 19H, wherein the passivating layerscomprise a transparent conductive oxide.

21H. The solar panel of clause 19H, wherein the super cells are arrangedin a single row, or in two or more parallel rows, to form a frontsurface of the solar panel to be illuminated by solar radiation duringoperation of the solar panel.

Z1. A solar module comprising:

a number N greater than or equal to about 250 rectangular orsubstantially rectangular silicon solar cells arranged as a plurality ofseries-connected super cells in two or more parallel rows, each supercell comprising a plurality of the silicon solar cells arranged in linewith long sides of adjacent silicon solar cells overlapping andconductively bonded directly to each other with an electrically andthermally conductive adhesive to electrically connect the silicon solarcells in the super cell in series; and

one or more bypass diodes;

wherein each pair of adjacent parallel rows in the solar module iselectrically connected by a bypass diode that is conductively bonded toa rear surface electrical contact on a centrally located solar cell inone row of the pair and conductively bonded to a rear surface electricalcontact on an adjacent solar cell in the other row of the pair.

Z2. The solar module of clause Z1, wherein each pair of adjacentparallel rows is electrically connected by at least one other bypassdiode that is conductively bonded to a rear surface electrical contacton a solar cell in one row of the pair and conductively bonded to a rearsurface electrical contact on an adjacent solar cell in the other row ofthe pair.

Z3. The solar module of clause Z2, wherein each pair of adjacentparallel rows is electrically connected by at least one other bypassdiode that is conductively bonded to a rear surface electrical contacton a solar cell in one row of the pair and conductively bonded to a rearsurface electrical contact on an adjacent solar cell in the other row ofthe pair.

Z4. The solar module of clause Z1, wherein the electrically andthermally conductive adhesive forms bonds between adjacent solar cellshaving a thickness perpendicular to the solar cells of less than orequal to about 50 micron and a thermal conductivity perpendicular to thesolar cells greater than or equal to about 1.5 W/(meter-K).

Z5. The solar module of clause Z1, wherein the super cells areencapsulated in a thermoplastic olefin layer between front and backglass sheets.

Z6. The solar module of clause Z1, wherein the conductive bonds betweenoverlapping solar cells provide mechanical compliance to the super cellsaccommodating a mismatch in thermal expansion between the super cellsand the glass front sheet in a direction parallel to the rows for atemperature range of about −40° C. to about 100° C. without damaging thesolar module.

Z7. The solar module of any of clauses Z1-Z6, wherein N is greater thanor equal to about 300, greater than or equal to about 350, greater thanor equal to about 400, greater than or equal to about 450, greater thanor equal to about 500, greater than or equal to about 550, greater thanor equal to about 600 greater than or equal to about 650, or greaterthan or equal to about 700.

Z8. The solar module of any of clauses Z1-Z7, wherein the super cellsare electrically connected to provide a high direct current voltage ofgreater than or equal to about 120 volts, greater than or equal to about180 volts, greater than or equal to about 240 volts, greater than orequal to about 300 volts, greater than or equal to about 360 volts,greater than or equal to about 420 volts, greater than or equal to about480 volts, greater than or equal to about 540 volts, or greater than orequal to about 600 volts.

Z9. A solar energy system comprising:

the solar module of clause Z1; and

an inverter electrically connected to the solar module and configured toconvert a DC output from the solar module to provide an AC output.

Z10. The solar energy system of clause Z9, wherein the inverter lacks aDC to DC boost component.

Z11. The solar energy system of clause Z9, wherein the inverter isconfigured to operate the solar module at a direct current voltage abovea minimum value set to avoid reverse biasing a solar cell.

Z12. The solar energy system of clause Z11, wherein the minimum voltagevalue is temperature dependent.

Z13. The solar energy system of clause Z9, wherein the inverter isconfigured to recognize a reverse bias condition and operate the solarmodule at a voltage that avoids the reverse bias condition.

Z14. The solar energy system of clause Z13, wherein the inverter isconfigured to operate the solar module in a local maximum region of thesolar module's voltage-current power curve to avoid the reverse biascondition.

Z15. The solar energy system of any of clauses Z9-Z14, wherein theinverter is a microinverter integrated with the solar module.

This disclosure is illustrative and not limiting. Further modificationswill be apparent to one skilled in the art in light of this disclosureand are intended to fall within the scope of the appended claims.

What is claimed is:
 1. A method comprising: scribing a solar cell waferto form a plurality of scribe lines in the solar cell wafer; applying anelectrically conductive bonding material to the solar cell wafer; andafter the applying the electrically conductive bonding material to thesolar cell wafer, separating the solar cell wafer along the scribe linesto provide solar cell strips.
 2. The method according to claim 1,wherein: each of the solar cell strips has a substantially rectangularshape with opposing first and second long edges and opposing first andsecond short edges; and one of the first and second long edges of eachof the solar cell strips includes the electrically conductive bondingmaterial.
 3. The method according to claim 2, further comprising:arranging first and second solar cell strips of the solar cell stripssuch that the first long edge of the first solar cell strip isoverlapped by the second long edge of the second solar cell strip withthe electrically conductive bonding material provided therebetween toelectrically connect the first and second solar cell strips in series.4. The method according to claim 1, wherein: the separating the solarcell wafer along the scribe lines provides at least a first, a second,and a third solar cell strip; the first solar cell strip includingopposing first and second long edges, opposing first and second shortedges, a first chamfered corner provided between the first short edgeand the first long edge, and a second chamfered corner provided betweenthe first long edge and first second short edge, where the first longedge is shorter than the second long edge; the second solar cell striphas a substantially rectangular shape, including opposing first andsecond long edges and opposing first and second short edges; and thesecond solar cell strip including opposing first and second long edges,opposing first and second short edges, a first chamfered corner providedbetween the first short edge and the second long edge, and a secondchamfered corner provided between the second long edge and the secondshort edge, where the second long edge is shorter than the first longedge.
 5. The method according to claim 4, further comprising arrangingthe first, the second, and the third solar cell strip such that: thesecond long edge of the first solar cell strip overlaps with the firstlong edge of the second solar cell strip with the electricallyconductive bonding material provided therebetween; and the second longedge of the second solar cell strip overlaps with the first long edge ofthe third solar cell strip with the electrically conductive bondingmaterial provided therebetween.
 6. The method according to claim 5,further comprising: providing a fourth solar cell strip withelectrically conductive bonding material, the fourth solar cell stripincluding opposing first and second long edges, opposing first andsecond short edges, a first chamfered corner provided between the firstshort edge and the first long edge, and a second chamfered cornerprovided between the first long edge and the second short edge, wherethe first long edge is shorter than the second long edge; and arrangingthe fourth solar cell strip with the third solar cell strip such thatthe second long edge of the third solar cell strip overlaps with thefirst long edge of the fourth solar cell strip with the electricallyconductive bonding material provided therebetween.
 7. The methodaccording to claim 1, wherein the separating includes applying a vacuumpressure to at least a portion of the solar cell wafer.
 8. The methodaccording to claim 7, further comprising: supporting the solar cellwafer with a perforated belt where the vacuum pressure is applied viaperforations in the perforated belt.
 9. The method according to claim 1,wherein each of the solar cell strips includes: a first long edge distalto a center of the solar cell wafer; a second long edge proximate to thecenter of the solar cell; first and second short edges between the firstand second long edges; and the applying the electrically conductivebonding material includes applying the electrically conductive bondingmaterial linearly along the first long edge of each of the solar cellstrips that is distal to the center of the solar cell wafer.
 10. Themethod according to claim 9, further comprising arranging first andsecond solar cell strips of the solar cell strips in an overlappingrelationship such that the electrically conductive bonding materialelectrically connects a top surface of the first long edge of the firstsolar cell strip to a rear surface of the second long edge of the secondsolar cell strip.
 11. The method according to claim 1, wherein thescribing includes laser scribing.
 12. The method according to claim 1,further comprising curing the electrically conductive bonding material.13. The method according to claim 1, wherein the scribing the solar cellwafer is performed after the applying the electrically conductivebonding material to the solar cell wafer.
 14. The method according toclaim 1, wherein the applying the electrically conductive bondingmaterial includes applying the electrically conductive bonding materialcontinuously or discontinuously.
 15. The method according to claim 1,wherein the applying the electrically conductive bonding material to thesolar cell wafer includes applying the electrically conductive bondingmaterial proximate to one of the scribe lines and along only one edge ofthe one of the scribe lines.
 16. A system, comprising: a scriber to forma plurality of scribe lines in a solar cell wafer; a printer to apply anelectrically conductive bonding material to the solar cell wafer; and abelt to, after the electrically conductive bonding material is appliedto the solar cell wafer, separate the solar cell wafer along the scribelines to provide solar cell strips.
 17. The system according to claim16, wherein the belt is a perforated belt and a vacuum manifold appliesa vacuum to a bottom surface of the solar cell wafer.
 18. The systemaccording to claim 16, wherein the printer is a screen, ink jet, or maskprinter.
 19. The system according to claim 16, wherein the scriber is alaser scriber.
 20. A system, comprising: means for scribing a solar cellwafer to form a plurality of scribe lines in the solar cell wafer; meansfor applying an electrically conductive bonding material to the solarcell wafer; and means for separating, after the applying theelectrically conductive bonding material to the solar cell wafer, thesolar cell wafer along the scribe lines to provide solar cell strips.